20631888 has 80 divisors (see below), whose sum is σ = 59787840. Its totient is φ = 6811776.

The previous prime is 20631869. The next prime is 20631899. The reversal of 20631888 is 88813602.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70270 + ... + 70562.

It is an arithmetic number, because the mean of its divisors is an integer number (747348).

Almost surely, 2^20631888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20631888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29893920).

20631888 is an abundant number, since it is smaller than the sum of its proper divisors (39155952).

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

20631888 is a wasteful number, since it uses less digits than its factorization.

20631888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473 (or 461 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 20631888 is about 4542.2338116834. The cubic root of 20631888 is about 274.2708529894.

The spelling of 20631888 in words is "twenty million, six hundred thirty-one thousand, eight hundred eighty-eight".