30991172 has 24 divisors (see below), whose sum is σ = 55543320. Its totient is φ = 15125760.

The previous prime is 30991171. The next prime is 30991183. The reversal of 30991172 is 27119903.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1223236 + 29767936 = 1106^2 + 5456^2 .

It is not an unprimeable number, because it can be changed into a prime (30991171) 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, 37904 + ... + 38712.

It is an arithmetic number, because the mean of its divisors is an integer number (2314305).

Almost surely, 2^30991172 is an apocalyptic number.

It is an amenable number.

30991172 is a deficient number, since it is larger than the sum of its proper divisors (24552148).

30991172 is a wasteful number, since it uses less digits than its factorization.

30991172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1031 (or 1029 counting only the distinct ones).

The product of its (nonzero) digits is 3402, while the sum is 32.

The square root of 30991172 is about 5566.9715285782. The cubic root of 30991172 is about 314.1082429367.

The spelling of 30991172 in words is "thirty million, nine hundred ninety-one thousand, one hundred seventy-two".