640820611325 has 6 divisors (see below), whose sum is σ = 794617558074. Its totient is φ = 512656489040.

The previous prime is 640820611283. The next prime is 640820611339. The reversal of 640820611325 is 523116028046.

It can be written as a sum of positive squares in 3 ways, for example, as 8894187481 + 631926423844 = 94309^2 + 794938^2 .

It is not a de Polignac number, because 640820611325 - 2⁸ = 640820611069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12816412202 + ... + 12816412251.

It is an arithmetic number, because the mean of its divisors is an integer number (132436259679).

Almost surely, 2^640820611325 is an apocalyptic number.

It is an amenable number.

640820611325 is a deficient number, since it is larger than the sum of its proper divisors (153796946749).

640820611325 is a wasteful number, since it uses less digits than its factorization.

640820611325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25632824463 (or 25632824458 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 38.

The spelling of 640820611325 in words is "six hundred forty billion, eight hundred twenty million, six hundred eleven thousand, three hundred twenty-five".