645452332631 has 4 divisors (see below), whose sum is σ = 673515477552. Its totient is φ = 617389187712.

The previous prime is 645452332561. The next prime is 645452332669. The reversal of 645452332631 is 136233254546.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645452332631 is a prime.

It is a super-2 number, since 2×645452332631² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645452332691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14031572426 + ... + 14031572471.

It is an arithmetic number, because the mean of its divisors is an integer number (168378869388).

Almost surely, 2^645452332631 is an apocalyptic number.

645452332631 is a deficient number, since it is larger than the sum of its proper divisors (28063144921).

645452332631 is a wasteful number, since it uses less digits than its factorization.

645452332631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28063144920.

The product of its digits is 1555200, while the sum is 44.

The spelling of 645452332631 in words is "six hundred forty-five billion, four hundred fifty-two million, three hundred thirty-two thousand, six hundred thirty-one".