30813840 has 60 divisors (see below), whose sum is σ = 103485564. Its totient is φ = 8216832.

The previous prime is 30813821. The next prime is 30813841. The reversal of 30813840 is 4831803.

It can be written as a sum of positive squares in 2 ways, for example, as 22240656 + 8573184 = 4716^2 + 2928^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30813841) 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, 20679 + ... + 22118.

Almost surely, 2^30813840 is an apocalyptic number.

30813840 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

30813840 is an abundant number, since it is smaller than the sum of its proper divisors (72671724).

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

30813840 is a wasteful number, since it uses less digits than its factorization.

30813840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42816 (or 42807 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 30813840 is about 5551.0215276109. The cubic root of 30813840 is about 313.5079857249.

The spelling of 30813840 in words is "thirty million, eight hundred thirteen thousand, eight hundred forty".