30312720 has 60 divisors (see below), whose sum is σ = 101802636. Its totient is φ = 8083200.

The previous prime is 30312713. The next prime is 30312749. The reversal of 30312720 is 2721303.

It can be written as a sum of positive squares in 2 ways, for example, as 17438976 + 12873744 = 4176^2 + 3588^2 .

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

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 30312693 and 30312702.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20331 + ... + 21770.

Almost surely, 2^30312720 is an apocalyptic number.

30312720 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

30312720 is an abundant number, since it is smaller than the sum of its proper divisors (71489916).

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

30312720 is a wasteful number, since it uses less digits than its factorization.

30312720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42120 (or 42111 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 18.

The square root of 30312720 is about 5505.6988657209. The cubic root of 30312720 is about 311.7991804344.

The spelling of 30312720 in words is "thirty million, three hundred twelve thousand, seven hundred twenty".