20631900 has 72 divisors (see below), whose sum is σ = 60395440. Its totient is φ = 5437440.

The previous prime is 20631899. The next prime is 20631907. The reversal of 20631900 is 913602.

It is a super-2 number, since 2×20631900² = 851350595220000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20631907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28746 + ... + 29454.

Almost surely, 2^20631900 is an apocalyptic number.

20631900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20631900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30197720).

20631900 is an abundant number, since it is smaller than the sum of its proper divisors (39763540).

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

20631900 is a wasteful number, since it uses less digits than its factorization.

20631900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 823 (or 816 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 20631900 is about 4542.2351326192. The cubic root of 20631900 is about 274.2709061636.

The spelling of 20631900 in words is "twenty million, six hundred thirty-one thousand, nine hundred".