645366240 has 288 divisors, whose sum is σ = 2392449696. Its totient is φ = 157777920.

The previous prime is 645366191. The next prime is 645366289. The reversal of 645366240 is 42663546.

645366240 is a `hidden beast` number, since 64 + 536 + 62 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (645366191) and next prime (645366289).

It is a tau number, because it is divible by the number of its divisors (288).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 645366195 and 645366204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1003359 + ... + 1004001.

It is an arithmetic number, because the mean of its divisors is an integer number (8307117).

Almost surely, 2^645366240 is an apocalyptic number.

645366240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645366240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1196224848).

645366240 is an abundant number, since it is smaller than the sum of its proper divisors (1747083456).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645366240 is a wasteful number, since it uses less digits than its factorization.

645366240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 722 (or 711 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The square root of 645366240 is about 25404.0595181164. The cubic root of 645366240 is about 864.1757615679.

The spelling of 645366240 in words is "six hundred forty-five million, three hundred sixty-six thousand, two hundred forty".