30720081 has 8 divisors (see below), whose sum is σ = 46811584. Its totient is φ = 17554320.

The previous prime is 30720073. The next prime is 30720083. The reversal of 30720081 is 18002703.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 30720081 - 2³ = 30720073 is a prime.

It is a super-2 number, since 2×30720081² = 1887446753293122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 1462861 = 30720081 / (3 + 0 + 7 + 2 + 0 + 0 + 8 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30720083) 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, 731410 + ... + 731451.

It is an arithmetic number, because the mean of its divisors is an integer number (5851448).

Almost surely, 2^30720081 is an apocalyptic number.

It is an amenable number.

30720081 is a deficient number, since it is larger than the sum of its proper divisors (16091503).

30720081 is a wasteful number, since it uses less digits than its factorization.

30720081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1462871.

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 30720081 is about 5542.5698913049. The cubic root of 30720081 is about 313.1896865574.

Adding to 30720081 its reverse (18002703), we get a palindrome (48722784).

The spelling of 30720081 in words is "thirty million, seven hundred twenty thousand, eighty-one".