21473073 has 8 divisors (see below), whose sum is σ = 31812000. Its totient is φ = 14315364.

The previous prime is 21473071. The next prime is 21473087. The reversal of 21473073 is 37037412.

It is not a de Polignac number, because 21473073 - 2¹ = 21473071 is a prime.

It is a super-2 number, since 2×21473073² = 922185728126658, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 795299 = 21473073 / (2 + 1 + 4 + 7 + 3 + 0 + 7 + 3).

It is not an unprimeable number, because it can be changed into a prime (21473071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 397623 + ... + 397676.

It is an arithmetic number, because the mean of its divisors is an integer number (3976500).

Almost surely, 2^21473073 is an apocalyptic number.

It is an amenable number.

21473073 is a deficient number, since it is larger than the sum of its proper divisors (10338927).

21473073 is an equidigital number, since it uses as much as digits as its factorization.

21473073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 795308 (or 795302 counting only the distinct ones).

The product of its (nonzero) digits is 3528, while the sum is 27.

The square root of 21473073 is about 4633.9047249593. The cubic root of 21473073 is about 277.9487552837.

The spelling of 21473073 in words is "twenty-one million, four hundred seventy-three thousand, seventy-three".