20871632 has 10 divisors (see below), whose sum is σ = 40438818. Its totient is φ = 10435808.

The previous prime is 20871629. The next prime is 20871637. The reversal of 20871632 is 23617802.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 10784656 + 10086976 = 3284^2 + 3176^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20871595 and 20871604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20871637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 652223 + ... + 652254.

Almost surely, 2^20871632 is an apocalyptic number.

It is an amenable number.

20871632 is a deficient number, since it is larger than the sum of its proper divisors (19567186).

20871632 is a wasteful number, since it uses less digits than its factorization.

20871632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1304485 (or 1304479 counting only the distinct ones).

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

The square root of 20871632 is about 4568.5481282351. The cubic root of 20871632 is about 275.3291134059.

The spelling of 20871632 in words is "twenty million, eight hundred seventy-one thousand, six hundred thirty-two".