21616906903 has 16 divisors (see below), whose sum is σ = 23288848704. Its totient is φ = 19990172160.

The previous prime is 21616906819. The next prime is 21616906919. The reversal of 21616906903 is 30960961612.

It is a de Polignac number, because none of the positive numbers 2^k-21616906903 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21616906903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21616916903) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 992001 + ... + 1013557.

It is an arithmetic number, because the mean of its divisors is an integer number (1455553044).

Almost surely, 2^21616906903 is an apocalyptic number.

21616906903 is a deficient number, since it is larger than the sum of its proper divisors (1671941801).

21616906903 is a wasteful number, since it uses less digits than its factorization.

21616906903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22602.

The product of its (nonzero) digits is 104976, while the sum is 43.

The spelling of 21616906903 in words is "twenty-one billion, six hundred sixteen million, nine hundred six thousand, nine hundred three".