31672991 has 4 divisors (see below), whose sum is σ = 36197712. Its totient is φ = 27148272.

The previous prime is 31672987. The next prime is 31673003. The reversal of 31672991 is 19927613.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19927613 = 73 ⋅272981.

It is a cyclic number.

It is not a de Polignac number, because 31672991 - 2² = 31672987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31672961) 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, 2262350 + ... + 2262363.

It is an arithmetic number, because the mean of its divisors is an integer number (9049428).

Almost surely, 2^31672991 is an apocalyptic number.

31672991 is a deficient number, since it is larger than the sum of its proper divisors (4524721).

31672991 is an equidigital number, since it uses as much as digits as its factorization.

31672991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4524720.

The product of its digits is 20412, while the sum is 38.

The square root of 31672991 is about 5627.8762424204. The cubic root of 31672991 is about 316.3950588267.

The spelling of 31672991 in words is "thirty-one million, six hundred seventy-two thousand, nine hundred ninety-one".