31421908 has 48 divisors (see below), whose sum is σ = 65253888. Its totient is φ = 12960000.

The previous prime is 31421881. The next prime is 31421939. The reversal of 31421908 is 80912413.

It is a happy number.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 115813 + ... + 116083.

It is an arithmetic number, because the mean of its divisors is an integer number (1359456).

Almost surely, 2^31421908 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 31421908, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32626944).

31421908 is an abundant number, since it is smaller than the sum of its proper divisors (33831980).

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

31421908 is a wasteful number, since it uses less digits than its factorization.

31421908 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 31421908 is about 5605.5247747200. The cubic root of 31421908 is about 315.5567812960.

31421908 divided by its sum of digits (28) gives a palindrome (1122211).

It can be divided in two parts, 3142 and 1908, that added together give a triangular number (5050 = T₁₀₀).

The spelling of 31421908 in words is "thirty-one million, four hundred twenty-one thousand, nine hundred eight".