31261289 has 8 divisors (see below), whose sum is σ = 32958240. Its totient is φ = 29569536.

The previous prime is 31261277. The next prime is 31261291. The reversal of 31261289 is 98216213.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31261289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31261889) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21194 + ... + 22620.

It is an arithmetic number, because the mean of its divisors is an integer number (4119780).

Almost surely, 2^31261289 is an apocalyptic number.

It is an amenable number.

31261289 is a deficient number, since it is larger than the sum of its proper divisors (1696951).

31261289 is a wasteful number, since it uses less digits than its factorization.

31261289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2599.

The product of its digits is 5184, while the sum is 32.

The square root of 31261289 is about 5591.1795714321. The cubic root of 31261289 is about 315.0181865707.

The spelling of 31261289 in words is "thirty-one million, two hundred sixty-one thousand, two hundred eighty-nine".