31129390 has 16 divisors (see below), whose sum is σ = 56801808. Its totient is φ = 12280896.

The previous prime is 31129379. The next prime is 31129409. The reversal of 31129390 is 9392113.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20592 + ... + 22051.

It is an arithmetic number, because the mean of its divisors is an integer number (3550113).

Almost surely, 2^31129390 is an apocalyptic number.

31129390 is a deficient number, since it is larger than the sum of its proper divisors (25672418).

31129390 is a wasteful number, since it uses less digits than its factorization.

31129390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42723.

The product of its (nonzero) digits is 1458, while the sum is 28.

The square root of 31129390 is about 5579.3718284409. The cubic root of 31129390 is about 314.5745158218.

The spelling of 31129390 in words is "thirty-one million, one hundred twenty-nine thousand, three hundred ninety".