20645161264 has 80 divisors (see below), whose sum is σ = 50818969600. Its totient is φ = 7903837440.

The previous prime is 20645161231. The next prime is 20645161291. The reversal of 20645161264 is 46216154602.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 183564 + ... + 273835.

It is an arithmetic number, because the mean of its divisors is an integer number (635237120).

Almost surely, 2^20645161264 is an apocalyptic number.

It is an amenable number.

20645161264 is an abundant number, since it is smaller than the sum of its proper divisors (30173808336).

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

20645161264 is a wasteful number, since it uses less digits than its factorization.

20645161264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457458 (or 457452 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 37.

The spelling of 20645161264 in words is "twenty billion, six hundred forty-five million, one hundred sixty-one thousand, two hundred sixty-four".