30406721 has 4 divisors (see below), whose sum is σ = 30646272. Its totient is φ = 30167172.

The previous prime is 30406709. The next prime is 30406723. The reversal of 30406721 is 12760403.

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 30406721 - 2⁶ = 30406657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30406723) 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, 119585 + ... + 119838.

It is an arithmetic number, because the mean of its divisors is an integer number (7661568).

Almost surely, 2^30406721 is an apocalyptic number.

It is an amenable number.

30406721 is a deficient number, since it is larger than the sum of its proper divisors (239551).

30406721 is a wasteful number, since it uses less digits than its factorization.

30406721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239550.

The product of its (nonzero) digits is 1008, while the sum is 23.

The square root of 30406721 is about 5514.2289578870. The cubic root of 30406721 is about 312.1211485747.

The spelling of 30406721 in words is "thirty million, four hundred six thousand, seven hundred twenty-one".