30993581 has 12 divisors (see below), whose sum is σ = 33213180. Its totient is φ = 28902720.

The previous prime is 30993577. The next prime is 30993587. The reversal of 30993581 is 18539903.

It can be written as a sum of positive squares in 2 ways, for example, as 1779556 + 29214025 = 1334^2 + 5405^2 .

It is not a de Polignac number, because 30993581 - 2² = 30993577 is a prime.

It is a super-2 number, since 2×30993581² = 1921204126407122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30993587) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20975 + ... + 22403.

It is an arithmetic number, because the mean of its divisors is an integer number (2767765).

Almost surely, 2^30993581 is an apocalyptic number.

It is an amenable number.

30993581 is a deficient number, since it is larger than the sum of its proper divisors (2219599).

30993581 is a wasteful number, since it uses less digits than its factorization.

30993581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1516 (or 1493 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 30993581 is about 5567.1878897698. The cubic root of 30993581 is about 314.1163814603.

The spelling of 30993581 in words is "thirty million, nine hundred ninety-three thousand, five hundred eighty-one".