31381329 has 8 divisors (see below), whose sum is σ = 47819200. Its totient is φ = 17932176.

The previous prime is 31381307. The next prime is 31381349. The reversal of 31381329 is 92318313.

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

It is not a de Polignac number, because 31381329 - 2⁵ = 31381297 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31381296 and 31381305.

It is not an unprimeable number, because it can be changed into a prime (31381349) 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, 747154 + ... + 747195.

It is an arithmetic number, because the mean of its divisors is an integer number (5977400).

Almost surely, 2^31381329 is an apocalyptic number.

It is an amenable number.

31381329 is a deficient number, since it is larger than the sum of its proper divisors (16437871).

31381329 is a wasteful number, since it uses less digits than its factorization.

31381329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1494359.

The product of its digits is 3888, while the sum is 30.

The square root of 31381329 is about 5601.9040513026. The cubic root of 31381329 is about 315.4208835989.

The spelling of 31381329 in words is "thirty-one million, three hundred eighty-one thousand, three hundred twenty-nine".