21216404165096 has 96 divisors (see below), whose sum is σ = 47948887931400. Its totient is φ = 8764969973760.

The previous prime is 21216404165053. The next prime is 21216404165101. The reversal of 21216404165096 is 69056140461212.

It can be written as a sum of positive squares in 4 ways, for example, as 13763580604900 + 7452823560196 = 3709930^2 + 2729986^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21216404165096.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5501636 + ... + 8526476.

Almost surely, 2^{21216404165096} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21216404165096, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23974443965700).

21216404165096 is an abundant number, since it is smaller than the sum of its proper divisors (26732483766304).

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

21216404165096 is a wasteful number, since it uses less digits than its factorization.

21216404165096 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3025507 (or 3025496 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 47.

The spelling of 21216404165096 in words is "twenty-one trillion, two hundred sixteen billion, four hundred four million, one hundred sixty-five thousand, ninety-six".