645059427840 has 800 divisors, whose sum is σ = 2489190967296. Its totient is φ = 159192760320.

The previous prime is 645059427839. The next prime is 645059427851. The reversal of 645059427840 is 48724950546.

645059427840 is a `hidden beast` number, since 6 + 4 + 5 + 0 + 594 + 2 + 7 + 8 + 40 = 666.

It is a super-2 number, since 2×645059427840² (a number of 24 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 147845499 + ... + 147849861.

Almost surely, 2^645059427840 is an apocalyptic number.

645059427840 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 645059427840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1244595483648).

645059427840 is an abundant number, since it is smaller than the sum of its proper divisors (1844131539456).

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

645059427840 is a wasteful number, since it uses less digits than its factorization.

645059427840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4452 (or 4427 counting only the distinct ones).

The product of its (nonzero) digits is 9676800, while the sum is 54.

The spelling of 645059427840 in words is "six hundred forty-five billion, fifty-nine million, four hundred twenty-seven thousand, eight hundred forty".