21696473 has 4 divisors (see below), whose sum is σ = 21826560. Its totient is φ = 21566388.

The previous prime is 21696457. The next prime is 21696487. The reversal of 21696473 is 37469612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21696473 - 2⁴ = 21696457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21696413) 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, 64793 + ... + 65126.

It is an arithmetic number, because the mean of its divisors is an integer number (5456640).

Almost surely, 2^21696473 is an apocalyptic number.

It is an amenable number.

21696473 is a deficient number, since it is larger than the sum of its proper divisors (130087).

21696473 is a wasteful number, since it uses less digits than its factorization.

21696473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130086.

The product of its digits is 54432, while the sum is 38.

The square root of 21696473 is about 4657.9472946782. The cubic root of 21696473 is about 278.9093327859.

The spelling of 21696473 in words is "twenty-one million, six hundred ninety-six thousand, four hundred seventy-three".