31977697 has 4 divisors (see below), whose sum is σ = 33858756. Its totient is φ = 30096640.

The previous prime is 31977679. The next prime is 31977707. The reversal of 31977697 is 79677913.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79677913 = 7 ⋅11382559.

It can be written as a sum of positive squares in 2 ways, for example, as 22953681 + 9024016 = 4791^2 + 3004^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31977697 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31977697.

It is not an unprimeable number, because it can be changed into a prime (31977667) 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, 940504 + ... + 940537.

It is an arithmetic number, because the mean of its divisors is an integer number (8464689).

Almost surely, 2^31977697 is an apocalyptic number.

It is an amenable number.

31977697 is a deficient number, since it is larger than the sum of its proper divisors (1881059).

31977697 is a wasteful number, since it uses less digits than its factorization.

31977697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1881058.

The product of its digits is 500094, while the sum is 49.

The square root of 31977697 is about 5654.8825805670. The cubic root of 31977697 is about 317.4064353229.

The spelling of 31977697 in words is "thirty-one million, nine hundred seventy-seven thousand, six hundred ninety-seven".