21696995401 has 3 divisors (see below), whose sum is σ = 21697142701. Its totient is φ = 21696848102.

The previous prime is 21696995393. The next prime is 21696995459. The reversal of 21696995401 is 10459969612.

It is a happy number.

The square root of 21696995401 is 147299.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 21696995401 - 2³ = 21696995393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21696995461) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 73650 + ... + 220948.

Almost surely, 2^21696995401 is an apocalyptic number.

21696995401 is the 147299-th square number.

21696995401 is the 73650-th centered octagonal number.

It is an amenable number.

21696995401 is a deficient number, since it is larger than the sum of its proper divisors (147300).

21696995401 is an frugal number, since it uses more digits than its factorization.

21696995401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294598 (or 147299 counting only the distinct ones).

The product of its (nonzero) digits is 1049760, while the sum is 52.

The spelling of 21696995401 in words is "twenty-one billion, six hundred ninety-six million, nine hundred ninety-five thousand, four hundred one".