21216404165144 has 16 divisors (see below), whose sum is σ = 39781819390320. Its totient is φ = 10607918994400.

The previous prime is 21216404165101. The next prime is 21216404165147. The reversal of 21216404165144 is 44156140461212.

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 3 ways as a sum of consecutive naturals, for example, 35067332 + ... + 35667219.

It is an arithmetic number, because the mean of its divisors is an integer number (2486363711895).

Almost surely, 2^{21216404165144} is an apocalyptic number.

It is an amenable number.

21216404165144 is a deficient number, since it is larger than the sum of its proper divisors (18565415225176).

21216404165144 is a wasteful number, since it uses less digits than its factorization.

21216404165144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70772050 (or 70772046 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 41.

The spelling of 21216404165144 in words is "twenty-one trillion, two hundred sixteen billion, four hundred four million, one hundred sixty-five thousand, one hundred forty-four".