20987508 has 12 divisors (see below), whose sum is σ = 48970880. Its totient is φ = 6995832.

The previous prime is 20987489. The next prime is 20987513. The reversal of 20987508 is 80578902.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 874468 + ... + 874491.

Almost surely, 2^20987508 is an apocalyptic number.

It is an amenable number.

20987508 is an abundant number, since it is smaller than the sum of its proper divisors (27983372).

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

20987508 is a wasteful number, since it uses less digits than its factorization.

20987508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1748966 (or 1748964 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 39.

The square root of 20987508 is about 4581.2125032572. The cubic root of 20987508 is about 275.8377012621.

The spelling of 20987508 in words is "twenty million, nine hundred eighty-seven thousand, five hundred eight".