20645818772 has 12 divisors (see below), whose sum is σ = 36319347456. Its totient is φ = 10268862360.

The previous prime is 20645818723. The next prime is 20645818799. The reversal of 20645818772 is 27781854602.

It is a self number, because there is not a number n which added to its sum of digits gives 20645818772.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13510898 + ... + 13512425.

It is an arithmetic number, because the mean of its divisors is an integer number (3026612288).

Almost surely, 2^20645818772 is an apocalyptic number.

It is an amenable number.

20645818772 is a deficient number, since it is larger than the sum of its proper divisors (15673528684).

20645818772 is a wasteful number, since it uses less digits than its factorization.

20645818772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27023518 (or 27023516 counting only the distinct ones).

The product of its (nonzero) digits is 1505280, while the sum is 50.

The spelling of 20645818772 in words is "twenty billion, six hundred forty-five million, eight hundred eighteen thousand, seven hundred seventy-two".