645757529040 has 640 divisors, whose sum is σ = 2422649940480. Its totient is φ = 157158309888.

The previous prime is 645757529033. The next prime is 645757529047. The reversal of 645757529040 is 40925757546.

It is a happy number.

645757529040 is a `hidden beast` number, since 6 + 4 + 5 + 7 + 575 + 29 + 0 + 40 = 666.

645757529040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (645757529033) and next prime (645757529047).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645757529047) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1491356664 + ... + 1491357096.

It is an arithmetic number, because the mean of its divisors is an integer number (3785390532).

Almost surely, 2^645757529040 is an apocalyptic number.

645757529040 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 645757529040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1211324970240).

645757529040 is an abundant number, since it is smaller than the sum of its proper divisors (1776892411440).

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

645757529040 is a wasteful number, since it uses less digits than its factorization.

645757529040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 948 (or 936 counting only the distinct ones).

The product of its (nonzero) digits is 10584000, while the sum is 54.

The spelling of 645757529040 in words is "six hundred forty-five billion, seven hundred fifty-seven million, five hundred twenty-nine thousand, forty".