31390090 has 16 divisors (see below), whose sum is σ = 59476320. Its totient is φ = 11895120.

The previous prime is 31390087. The next prime is 31390091. The reversal of 31390090 is 9009313.

It is a super-3 number, since 3×31390090³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (31390091) 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, 82416 + ... + 82795.

It is an arithmetic number, because the mean of its divisors is an integer number (3717270).

Almost surely, 2^31390090 is an apocalyptic number.

31390090 is a deficient number, since it is larger than the sum of its proper divisors (28086230).

31390090 is a wasteful number, since it uses less digits than its factorization.

31390090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165237.

The product of its (nonzero) digits is 729, while the sum is 25.

The square root of 31390090 is about 5602.6859630002. The cubic root of 31390090 is about 315.4502338031.

The spelling of 31390090 in words is "thirty-one million, three hundred ninety thousand, ninety".