645431322511 has 16 divisors (see below), whose sum is σ = 684546629760. Its totient is φ = 606444167680.

The previous prime is 645431322509. The next prime is 645431322553. The reversal of 645431322511 is 115223134546.

It is a cyclic number.

It is not a de Polignac number, because 645431322511 - 2¹ = 645431322509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645431322581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64300185 + ... + 64310221.

It is an arithmetic number, because the mean of its divisors is an integer number (42784164360).

Almost surely, 2^645431322511 is an apocalyptic number.

645431322511 is a deficient number, since it is larger than the sum of its proper divisors (39115307249).

645431322511 is a wasteful number, since it uses less digits than its factorization.

645431322511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16034.

The product of its digits is 86400, while the sum is 37.

The spelling of 645431322511 in words is "six hundred forty-five billion, four hundred thirty-one million, three hundred twenty-two thousand, five hundred eleven".