21487292 has 12 divisors (see below), whose sum is σ = 37821336. Its totient is φ = 10681200.

The previous prime is 21487283. The next prime is 21487307. The reversal of 21487292 is 29278412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14834 + ... + 16217.

It is an arithmetic number, because the mean of its divisors is an integer number (3151778).

Almost surely, 2^21487292 is an apocalyptic number.

It is an amenable number.

21487292 is a deficient number, since it is larger than the sum of its proper divisors (16334044).

21487292 is a wasteful number, since it uses less digits than its factorization.

21487292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31228 (or 31226 counting only the distinct ones).

The product of its digits is 16128, while the sum is 35.

The square root of 21487292 is about 4635.4387063146. The cubic root of 21487292 is about 278.0100922789.

The spelling of 21487292 in words is "twenty-one million, four hundred eighty-seven thousand, two hundred ninety-two".