30813561 has 8 divisors (see below), whose sum is σ = 45649760. Its totient is φ = 20542356.

The previous prime is 30813557. The next prime is 30813577. The reversal of 30813561 is 16531803.

30813561 is a `hidden beast` number, since 308 + 1 + 356 + 1 = 666.

It is not a de Polignac number, because 30813561 - 2² = 30813557 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 1141243 = 30813561 / (3 + 0 + 8 + 1 + 3 + 5 + 6 + 1).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (30813521) 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, 570595 + ... + 570648.

It is an arithmetic number, because the mean of its divisors is an integer number (5706220).

Almost surely, 2^30813561 is an apocalyptic number.

It is an amenable number.

30813561 is a deficient number, since it is larger than the sum of its proper divisors (14836199).

30813561 is a wasteful number, since it uses less digits than its factorization.

30813561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1141252 (or 1141246 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 30813561 is about 5550.9963970444. The cubic root of 30813561 is about 313.5070395159.

The spelling of 30813561 in words is "thirty million, eight hundred thirteen thousand, five hundred sixty-one".