30999938 has 18 divisors (see below), whose sum is σ = 48429603. Its totient is φ = 14881860.

The previous prime is 30999937. The next prime is 30999953. The reversal of 30999938 is 83999903.

It can be written as a sum of positive squares in only one way, i.e., 15499969 + 15499969 = 3937^2 + 3937^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3937.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30999937) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 244031 + ... + 244157.

Almost surely, 2^30999938 is an apocalyptic number.

30999938 is a deficient number, since it is larger than the sum of its proper divisors (17429665).

30999938 is an equidigital number, since it uses as much as digits as its factorization.

30999938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318 (or 160 counting only the distinct ones).

The product of its (nonzero) digits is 472392, while the sum is 50.

The square root of 30999938 is about 5567.7587950629. The cubic root of 30999938 is about 314.1378558136.

Multiplying 30999938 by its sum of digits (50), we get a square (1549996900 = 39370²).

Multiplying 30999938 by its product of nonzero digits (472392), we get a square (14644122711696 = 3826764²).

The spelling of 30999938 in words is "thirty million, nine hundred ninety-nine thousand, nine hundred thirty-eight".