21473156 has 6 divisors (see below), whose sum is σ = 37578030. Its totient is φ = 10736576.

The previous prime is 21473147. The next prime is 21473171. The reversal of 21473156 is 65137412.

It can be written as a sum of positive squares in only one way, i.e., 18783556 + 2689600 = 4334^2 + 1640^2 .

It is a super-2 number, since 2×21473156² = 922192857200672, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2684141 + ... + 2684148.

It is an arithmetic number, because the mean of its divisors is an integer number (6263005).

Almost surely, 2^21473156 is an apocalyptic number.

It is an amenable number.

21473156 is a deficient number, since it is larger than the sum of its proper divisors (16104874).

21473156 is a wasteful number, since it uses less digits than its factorization.

21473156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5368293 (or 5368291 counting only the distinct ones).

The product of its digits is 5040, while the sum is 29.

The square root of 21473156 is about 4633.9136806807. The cubic root of 21473156 is about 277.9491134022.

The spelling of 21473156 in words is "twenty-one million, four hundred seventy-three thousand, one hundred fifty-six".