21631662 has 48 divisors (see below), whose sum is σ = 50865360. Its totient is φ = 6643728.

The previous prime is 21631639. The next prime is 21631663. The reversal of 21631662 is 26613612.

21631662 is a `hidden beast` number, since 21 + 631 + 6 + 6 + 2 = 666.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21631663) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 39273 + ... + 39819.

It is an arithmetic number, because the mean of its divisors is an integer number (1059695).

Almost surely, 2^21631662 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21631662, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25432680).

21631662 is an abundant number, since it is smaller than the sum of its proper divisors (29233698).

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

21631662 is a wasteful number, since it uses less digits than its factorization.

21631662 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 594 (or 565 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 21631662 is about 4650.9850569530. The cubic root of 21631662 is about 278.6313394953.

It can be divided in two parts, 216 and 31662, that added together give a triangular number (31878 = T₂₅₂).

The spelling of 21631662 in words is "twenty-one million, six hundred thirty-one thousand, six hundred sixty-two".