645132652521 has 64 divisors (see below), whose sum is σ = 1002891456000. Its totient is φ = 361296562176.

The previous prime is 645132652517. The next prime is 645132652523. The reversal of 645132652521 is 125256231546.

It is not a de Polignac number, because 645132652521 - 2² = 645132652517 is a prime.

It is a super-2 number, since 2×645132652521² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (645132652523) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 112841755 + ... + 112847471.

It is an arithmetic number, because the mean of its divisors is an integer number (15670179000).

Almost surely, 2^645132652521 is an apocalyptic number.

It is an amenable number.

645132652521 is a deficient number, since it is larger than the sum of its proper divisors (357758803479).

645132652521 is a wasteful number, since it uses less digits than its factorization.

645132652521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6338.

The product of its digits is 432000, while the sum is 42.

The spelling of 645132652521 in words is "six hundred forty-five billion, one hundred thirty-two million, six hundred fifty-two thousand, five hundred twenty-one".