21092473 has 4 divisors (see below), whose sum is σ = 21209188. Its totient is φ = 20975760.

The previous prime is 21092459. The next prime is 21092501. The reversal of 21092473 is 37429012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5702544 + 15389929 = 2388^2 + 3923^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21092473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21090473) 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, 58086 + ... + 58447.

It is an arithmetic number, because the mean of its divisors is an integer number (5302297).

Almost surely, 2^21092473 is an apocalyptic number.

It is an amenable number.

21092473 is a deficient number, since it is larger than the sum of its proper divisors (116715).

21092473 is a wasteful number, since it uses less digits than its factorization.

21092473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116714.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 21092473 is about 4592.6542434631. The cubic root of 21092473 is about 276.2967865721.

The spelling of 21092473 in words is "twenty-one million, ninety-two thousand, four hundred seventy-three".