645253626352540 has 12 divisors (see below), whose sum is σ = 1355032615340376. Its totient is φ = 258101450541008.

The previous prime is 645253626352537. The next prime is 645253626352541. The reversal of 645253626352540 is 45253626352546.

It is a super-2 number, since 2×645253626352540² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645253626352541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16131340658794 + ... + 16131340658833.

It is an arithmetic number, because the mean of its divisors is an integer number (112919384611698).

Almost surely, 2^{645253626352540} is an apocalyptic number.

It is an amenable number.

645253626352540 is an abundant number, since it is smaller than the sum of its proper divisors (709778988987836).

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

645253626352540 is a wasteful number, since it uses less digits than its factorization.

645253626352540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32262681317636 (or 32262681317634 counting only the distinct ones).

The product of its (nonzero) digits is 155520000, while the sum is 58.

The spelling of 645253626352540 in words is "six hundred forty-five trillion, two hundred fifty-three billion, six hundred twenty-six million, three hundred fifty-two thousand, five hundred forty".