31377985 has 4 divisors (see below), whose sum is σ = 37653588. Its totient is φ = 25102384.

The previous prime is 31377977. The next prime is 31377991. The reversal of 31377985 is 58977313.

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

It can be written as a sum of positive squares in 2 ways, for example, as 18931201 + 12446784 = 4351^2 + 3528^2 .

It is a cyclic number.

It is not a de Polignac number, because 31377985 - 2³ = 31377977 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 3137794 + ... + 3137803.

It is an arithmetic number, because the mean of its divisors is an integer number (9413397).

Almost surely, 2^31377985 is an apocalyptic number.

It is an amenable number.

31377985 is a deficient number, since it is larger than the sum of its proper divisors (6275603).

31377985 is an equidigital number, since it uses as much as digits as its factorization.

31377985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6275602.

The product of its digits is 158760, while the sum is 43.

The square root of 31377985 is about 5601.6055734048. The cubic root of 31377985 is about 315.4096794324.

The spelling of 31377985 in words is "thirty-one million, three hundred seventy-seven thousand, nine hundred eighty-five".