21216404055402 has 24 divisors (see below), whose sum is σ = 45972508988484. Its totient is φ = 7071575679744.

The previous prime is 21216404055397. The next prime is 21216404055433. The reversal of 21216404055402 is 20455040461212.

21216404055402 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 64 + 0 + 40 + 554 + 0 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 19426858423281 + 1789545632121 = 4407591^2 + 1337739^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46349703 + ... + 46805210.

Almost surely, 2^{21216404055402} is an apocalyptic number.

21216404055402 is an abundant number, since it is smaller than the sum of its proper divisors (24756104933082).

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

21216404055402 is a wasteful number, since it uses less digits than its factorization.

21216404055402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93167574 (or 93167571 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

The spelling of 21216404055402 in words is "twenty-one trillion, two hundred sixteen billion, four hundred four million, fifty-five thousand, four hundred two".