31009397 has 4 divisors (see below), whose sum is σ = 31535040. Its totient is φ = 30483756.

The previous prime is 31009373. The next prime is 31009421. The reversal of 31009397 is 79390013.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (31009373) and next prime (31009421).

It is a cyclic number.

It is not a de Polignac number, because 31009397 - 2²⁴ = 14232181 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 (31009327) 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, 262733 + ... + 262850.

It is an arithmetic number, because the mean of its divisors is an integer number (7883760).

Almost surely, 2^31009397 is an apocalyptic number.

It is an amenable number.

31009397 is a deficient number, since it is larger than the sum of its proper divisors (525643).

31009397 is an equidigital number, since it uses as much as digits as its factorization.

31009397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525642.

The product of its (nonzero) digits is 5103, while the sum is 32.

The square root of 31009397 is about 5568.6081744005. The cubic root of 31009397 is about 314.1698034883.

The spelling of 31009397 in words is "thirty-one million, nine thousand, three hundred ninety-seven".