31634921 has 4 divisors (see below), whose sum is σ = 32107152. Its totient is φ = 31162692.

The previous prime is 31634891. The next prime is 31634927. The reversal of 31634921 is 12943613.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12943613 = 17 ⋅761389.

It is a cyclic number.

It is not a de Polignac number, because 31634921 - 2⁶ = 31634857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31634927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 236015 + ... + 236148.

It is an arithmetic number, because the mean of its divisors is an integer number (8026788).

Almost surely, 2^31634921 is an apocalyptic number.

It is an amenable number.

31634921 is a deficient number, since it is larger than the sum of its proper divisors (472231).

31634921 is an equidigital number, since it uses as much as digits as its factorization.

31634921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472230.

The product of its digits is 3888, while the sum is 29.

The square root of 31634921 is about 5624.4929549249. The cubic root of 31634921 is about 316.2682421635.

The spelling of 31634921 in words is "thirty-one million, six hundred thirty-four thousand, nine hundred twenty-one".