31479991 has 4 divisors (see below), whose sum is σ = 31859352. Its totient is φ = 31100632.

The previous prime is 31479961. The next prime is 31480019. The reversal of 31479991 is 19997413.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31479991 - 2¹³ = 31471799 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 (31479961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 189556 + ... + 189721.

It is an arithmetic number, because the mean of its divisors is an integer number (7964838).

Almost surely, 2^31479991 is an apocalyptic number.

31479991 is a deficient number, since it is larger than the sum of its proper divisors (379361).

31479991 is an equidigital number, since it uses as much as digits as its factorization.

31479991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379360.

The product of its digits is 61236, while the sum is 43.

The square root of 31479991 is about 5610.7032536038. The cubic root of 31479991 is about 315.7510958571.

The spelling of 31479991 in words is "thirty-one million, four hundred seventy-nine thousand, nine hundred ninety-one".