21608487 has 12 divisors (see below), whose sum is σ = 31500040. Its totient is φ = 14272848.

The previous prime is 21608467. The next prime is 21608497. The reversal of 21608487 is 78480612.

21608487 is a `hidden beast` number, since 2 + 1 + 608 + 48 + 7 = 666.

It is not a de Polignac number, because 21608487 - 2⁷ = 21608359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21608417) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10033 + ... + 11994.

Almost surely, 2^21608487 is an apocalyptic number.

21608487 is a deficient number, since it is larger than the sum of its proper divisors (9891553).

21608487 is a wasteful number, since it uses less digits than its factorization.

21608487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22142 (or 22139 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 21608487 is about 4648.4929816017. The cubic root of 21608487 is about 278.5318003928.

The spelling of 21608487 in words is "twenty-one million, six hundred eight thousand, four hundred eighty-seven".