21216404165143 has 12 divisors (see below), whose sum is σ = 24547905648280. Its totient is φ = 18272501192880.

The previous prime is 21216404165101. The next prime is 21216404165147. The reversal of 21216404165143 is 34156140461212.

It is a de Polignac number, because none of the positive numbers 2^k-21216404165143 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21216404165096 and 21216404165105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21216404165147) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4614265680 + ... + 4614270277.

Almost surely, 2^{21216404165143} is an apocalyptic number.

21216404165143 is a deficient number, since it is larger than the sum of its proper divisors (3331501483137).

21216404165143 is a wasteful number, since it uses less digits than its factorization.

21216404165143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9228535998 (or 9228535987 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 40.

The spelling of 21216404165143 in words is "twenty-one trillion, two hundred sixteen billion, four hundred four million, one hundred sixty-five thousand, one hundred forty-three".