21171458 has 16 divisors (see below), whose sum is σ = 39593664. Its totient is φ = 8248560.

The previous prime is 21171407. The next prime is 21171461. The reversal of 21171458 is 85417112.

It is a self number, because there is not a number n which added to its sum of digits gives 21171458.

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, 68585 + ... + 68892.

It is an arithmetic number, because the mean of its divisors is an integer number (2474604).

Almost surely, 2^21171458 is an apocalyptic number.

21171458 is a deficient number, since it is larger than the sum of its proper divisors (18422206).

21171458 is a wasteful number, since it uses less digits than its factorization.

21171458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137497.

The product of its digits is 2240, while the sum is 29.

The square root of 21171458 is about 4601.2452662296. The cubic root of 21171458 is about 276.6412399013.

The spelling of 21171458 in words is "twenty-one million, one hundred seventy-one thousand, four hundred fifty-eight".