21157026 has 16 divisors (see below), whose sum is σ = 46160928. Its totient is φ = 6411200.

The previous prime is 21156953. The next prime is 21157039. The reversal of 21157026 is 62075112.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 21156987 and 21157005.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 160215 + ... + 160346.

It is an arithmetic number, because the mean of its divisors is an integer number (2885058).

Almost surely, 2^21157026 is an apocalyptic number.

21157026 is an abundant number, since it is smaller than the sum of its proper divisors (25003902).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21157026 is a wasteful number, since it uses less digits than its factorization.

21157026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320577.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 21157026 is about 4599.6767277712. The cubic root of 21157026 is about 276.5783660405.

The spelling of 21157026 in words is "twenty-one million, one hundred fifty-seven thousand, twenty-six".