20871508 has 24 divisors (see below), whose sum is σ = 42154112. Its totient is φ = 8856864.

The previous prime is 20871497. The next prime is 20871509. The reversal of 20871508 is 80517802.

It is a self number, because there is not a number n which added to its sum of digits gives 20871508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20871509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 735 + ... + 6502.

Almost surely, 2^20871508 is an apocalyptic number.

20871508 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20871508 is an abundant number, since it is smaller than the sum of its proper divisors (21282604).

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

20871508 is a wasteful number, since it uses less digits than its factorization.

20871508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7351 (or 7349 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 31.

The square root of 20871508 is about 4568.5345571638. The cubic root of 20871508 is about 275.3285681542.

The spelling of 20871508 in words is "twenty million, eight hundred seventy-one thousand, five hundred eight".