31116389 has 4 divisors (see below), whose sum is σ = 31554720. Its totient is φ = 30678060.

The previous prime is 31116377. The next prime is 31116427. The reversal of 31116389 is 98361113.

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, and also an emirpimes, since its reverse is a distinct semiprime: 98361113 = 349 ⋅281837.

It is a cyclic number.

It is not a de Polignac number, because 31116389 - 2⁴ = 31116373 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 (31116329) 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, 219059 + ... + 219200.

It is an arithmetic number, because the mean of its divisors is an integer number (7888680).

Almost surely, 2^31116389 is an apocalyptic number.

It is an amenable number.

31116389 is a deficient number, since it is larger than the sum of its proper divisors (438331).

31116389 is an equidigital number, since it uses as much as digits as its factorization.

31116389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438330.

The product of its digits is 3888, while the sum is 32.

The square root of 31116389 is about 5578.2066114478. The cubic root of 31116389 is about 314.5307163473.

The spelling of 31116389 in words is "thirty-one million, one hundred sixteen thousand, three hundred eighty-nine".