21694616738 has 16 divisors (see below), whose sum is σ = 33959920896. Its totient is φ = 10374730080.

The previous prime is 21694616717. The next prime is 21694616743. The reversal of 21694616738 is 83761649612.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21694616738.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 951095 + ... + 973637.

It is an arithmetic number, because the mean of its divisors is an integer number (2122495056).

Almost surely, 2^21694616738 is an apocalyptic number.

21694616738 is a deficient number, since it is larger than the sum of its proper divisors (12265304158).

21694616738 is a wasteful number, since it uses less digits than its factorization.

21694616738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43489.

The product of its digits is 2612736, while the sum is 53.

The spelling of 21694616738 in words is "twenty-one billion, six hundred ninety-four million, six hundred sixteen thousand, seven hundred thirty-eight".