21031222220388 has 72 divisors (see below), whose sum is σ = 56194413475200. Its totient is φ = 6613650098496.

The previous prime is 21031222220329. The next prime is 21031222220389. The reversal of 21031222220388 is 88302222213012.

21031222220388 is a `hidden beast` number, since 2 + 1 + 0 + 31 + 2 + 22 + 220 + 388 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21031222220389) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 64161631 + ... + 64488582.

Almost surely, 2^{21031222220388} is an apocalyptic number.

It is an amenable number.

21031222220388 is an abundant number, since it is smaller than the sum of its proper divisors (35163191254812).

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

21031222220388 is a wasteful number, since it uses less digits than its factorization.

21031222220388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128650481 (or 128650476 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The spelling of 21031222220388 in words is "twenty-one trillion, thirty-one billion, two hundred twenty-two million, two hundred twenty thousand, three hundred eighty-eight".