20871801 has 12 divisors (see below), whose sum is σ = 31921812. Its totient is φ = 13095936.

The previous prime is 20871769. The next prime is 20871853. The reversal of 20871801 is 10817802.

It can be written as a sum of positive squares in 2 ways, for example, as 19184400 + 1687401 = 4380^2 + 1299^2 .

It is not a de Polignac number, because 20871801 - 2⁵ = 20871769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20871881) 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, 68056 + ... + 68361.

It is an arithmetic number, because the mean of its divisors is an integer number (2660151).

Almost surely, 2^20871801 is an apocalyptic number.

It is an amenable number.

20871801 is a deficient number, since it is larger than the sum of its proper divisors (11050011).

20871801 is a wasteful number, since it uses less digits than its factorization.

20871801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136440 (or 136437 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 20871801 is about 4568.5666242269. The cubic root of 20871801 is about 275.3298565277.

The spelling of 20871801 in words is "twenty million, eight hundred seventy-one thousand, eight hundred one".