20397640212 has 24 divisors (see below), whose sum is σ = 52882771200. Its totient is φ = 6799213368.

The previous prime is 20397640199. The next prime is 20397640253. The reversal of 20397640212 is 21204679302.

20397640212 is a `hidden beast` number, since 2 + 0 + 3 + 9 + 7 + 640 + 2 + 1 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94433412 + ... + 94433627.

It is an arithmetic number, because the mean of its divisors is an integer number (2203448800).

Almost surely, 2^20397640212 is an apocalyptic number.

It is an amenable number.

20397640212 is an abundant number, since it is smaller than the sum of its proper divisors (32485130988).

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

20397640212 is a wasteful number, since it uses less digits than its factorization.

20397640212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188867052 (or 188867044 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The spelling of 20397640212 in words is "twenty billion, three hundred ninety-seven million, six hundred forty thousand, two hundred twelve".