30664721 has 4 divisors (see below), whose sum is σ = 30703344. Its totient is φ = 30626100.

The previous prime is 30664709. The next prime is 30664741. The reversal of 30664721 is 12746603.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 30664721 - 2⁶ = 30664657 is a prime.

It is a super-2 number, since 2×30664721² = 1880650228015682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30664741) 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, 18095 + ... + 19716.

It is an arithmetic number, because the mean of its divisors is an integer number (7675836).

Almost surely, 2^30664721 is an apocalyptic number.

It is an amenable number.

30664721 is a deficient number, since it is larger than the sum of its proper divisors (38623).

30664721 is an equidigital number, since it uses as much as digits as its factorization.

30664721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38622.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 30664721 is about 5537.5735661028. The cubic root of 30664721 is about 313.0014426266.

The spelling of 30664721 in words is "thirty million, six hundred sixty-four thousand, seven hundred twenty-one".