30991432 has 32 divisors (see below), whose sum is σ = 62337600. Its totient is φ = 14399424.

The previous prime is 30991421. The next prime is 30991439. The reversal of 30991432 is 23419903.

It is a junction number, because it is equal to n+sod(n) for n = 30991394 and 30991403.

It is not an unprimeable number, because it can be changed into a prime (30991439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6133 + ... + 9979.

It is an arithmetic number, because the mean of its divisors is an integer number (1948050).

Almost surely, 2^30991432 is an apocalyptic number.

It is an amenable number.

30991432 is an abundant number, since it is smaller than the sum of its proper divisors (31346168).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

30991432 is a wasteful number, since it uses less digits than its factorization.

30991432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3925 (or 3921 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 30991432 is about 5566.9948805437. The cubic root of 30991432 is about 314.1091213365.

The spelling of 30991432 in words is "thirty million, nine hundred ninety-one thousand, four hundred thirty-two".