20871236 has 6 divisors (see below), whose sum is σ = 36524670. Its totient is φ = 10435616.

The previous prime is 20871229. The next prime is 20871251. The reversal of 20871236 is 63217802.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 14868736 + 6002500 = 3856^2 + 2450^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20871199 and 20871208.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2608901 + ... + 2608908.

It is an arithmetic number, because the mean of its divisors is an integer number (6087445).

Almost surely, 2^20871236 is an apocalyptic number.

It is an amenable number.

20871236 is a deficient number, since it is larger than the sum of its proper divisors (15653434).

20871236 is a wasteful number, since it uses less digits than its factorization.

20871236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5217813 (or 5217811 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 20871236 is about 4568.5047882212. The cubic root of 20871236 is about 275.3273721106.

The spelling of 20871236 in words is "twenty million, eight hundred seventy-one thousand, two hundred thirty-six".