21087484 has 24 divisors (see below), whose sum is σ = 41349168. Its totient is φ = 9325440.

The previous prime is 21087457. The next prime is 21087491. The reversal of 21087484 is 48478012.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

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, 4849 + ... + 8104.

It is an arithmetic number, because the mean of its divisors is an integer number (1722882).

Almost surely, 2^21087484 is an apocalyptic number.

It is an amenable number.

21087484 is a deficient number, since it is larger than the sum of its proper divisors (20261684).

21087484 is a wasteful number, since it uses less digits than its factorization.

21087484 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13005 (or 13003 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 34.

The square root of 21087484 is about 4592.1110613747. Note that the first 3 decimals coincide. The cubic root of 21087484 is about 276.2750007062.

The spelling of 21087484 in words is "twenty-one million, eighty-seven thousand, four hundred eighty-four".