30861720 has 96 divisors (see below), whose sum is σ = 102070800. Its totient is φ = 8084736.

The previous prime is 30861703. The next prime is 30861739. The reversal of 30861720 is 2716803.

It is a super-2 number, since 2×30861720² = 1904891522716800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20514 + ... + 21966.

Almost surely, 2^30861720 is an apocalyptic number.

30861720 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30861720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51035400).

30861720 is an abundant number, since it is smaller than the sum of its proper divisors (71209080).

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

30861720 is a wasteful number, since it uses less digits than its factorization.

30861720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1529 (or 1522 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 30861720 is about 5555.3325733029. The cubic root of 30861720 is about 313.6702828642.

The spelling of 30861720 in words is "thirty million, eight hundred sixty-one thousand, seven hundred twenty".