31008997 has 8 divisors (see below), whose sum is σ = 32625432. Its totient is φ = 29433600.

The previous prime is 31008983. The next prime is 31009009. The reversal of 31008997 is 79980013.

It can be written as a sum of positive squares in 4 ways, for example, as 7834401 + 23174596 = 2799^2 + 4814^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31008997 - 2¹¹ = 31006949 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31000997) 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 7 ways as a sum of consecutive naturals, for example, 8704 + ... + 11737.

It is an arithmetic number, because the mean of its divisors is an integer number (4078179).

Almost surely, 2^31008997 is an apocalyptic number.

31008997 is a gapful number since it is divisible by the number (37) formed by its first and last digit.

It is an amenable number.

31008997 is a deficient number, since it is larger than the sum of its proper divisors (1616435).

31008997 is a wasteful number, since it uses less digits than its factorization.

31008997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20519.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 31008997 is about 5568.5722586674. The cubic root of 31008997 is about 314.1684526240.

The spelling of 31008997 in words is "thirty-one million, eight thousand, nine hundred ninety-seven".