30685813 has 4 divisors (see below), whose sum is σ = 30719500. Its totient is φ = 30652128.

The previous prime is 30685801. The next prime is 30685819. The reversal of 30685813 is 31858603.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4235364 + 26450449 = 2058^2 + 5143^2 .

It is a cyclic number.

It is not a de Polignac number, because 30685813 - 2⁹ = 30685301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30685819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15438 + ... + 17311.

It is an arithmetic number, because the mean of its divisors is an integer number (7679875).

Almost surely, 2^30685813 is an apocalyptic number.

It is an amenable number.

30685813 is a deficient number, since it is larger than the sum of its proper divisors (33687).

30685813 is an equidigital number, since it uses as much as digits as its factorization.

30685813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33686.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 30685813 is about 5539.4776829589. The cubic root of 30685813 is about 313.0731897152.

The spelling of 30685813 in words is "thirty million, six hundred eighty-five thousand, eight hundred thirteen".