645138222624 has 216 divisors, whose sum is σ = 2246464387440. Its totient is φ = 174623807232.

The previous prime is 645138222613. The next prime is 645138222637. The reversal of 645138222624 is 426222831546.

It is a happy number.

645138222624 is a `hidden beast` number, since 6 + 4 + 5 + 1 + 382 + 2 + 262 + 4 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 645138222624.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 934914 + ... + 1471169.

It is an arithmetic number, because the mean of its divisors is an integer number (10400298090).

Almost surely, 2^645138222624 is an apocalyptic number.

It is an amenable number.

645138222624 is an abundant number, since it is smaller than the sum of its proper divisors (1601326164816).

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

645138222624 is a wasteful number, since it uses less digits than its factorization.

645138222624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2406132 (or 2406114 counting only the distinct ones).

The product of its digits is 1105920, while the sum is 45.

The spelling of 645138222624 in words is "six hundred forty-five billion, one hundred thirty-eight million, two hundred twenty-two thousand, six hundred twenty-four".