21694445956 has 6 divisors (see below), whose sum is σ = 37965280430. Its totient is φ = 10847222976.

The previous prime is 21694445939. The next prime is 21694445987. The reversal of 21694445956 is 65954449612.

It can be written as a sum of positive squares in only one way, i.e., 21280974400 + 413471556 = 145880^2 + 20334^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21694445897 and 21694445906.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2711805741 + ... + 2711805748.

Almost surely, 2^21694445956 is an apocalyptic number.

It is an amenable number.

21694445956 is a deficient number, since it is larger than the sum of its proper divisors (16270834474).

21694445956 is a wasteful number, since it uses less digits than its factorization.

21694445956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5423611493 (or 5423611491 counting only the distinct ones).

The product of its digits is 9331200, while the sum is 55.

The spelling of 21694445956 in words is "twenty-one billion, six hundred ninety-four million, four hundred forty-five thousand, nine hundred fifty-six".