30721406 has 4 divisors (see below), whose sum is σ = 46082112. Its totient is φ = 15360702.

The previous prime is 30721391. The next prime is 30721417. The reversal of 30721406 is 60412703.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7680350 + ... + 7680353.

It is an arithmetic number, because the mean of its divisors is an integer number (11520528).

Almost surely, 2^30721406 is an apocalyptic number.

30721406 is a deficient number, since it is larger than the sum of its proper divisors (15360706).

30721406 is a wasteful number, since it uses less digits than its factorization.

30721406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15360705.

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

The square root of 30721406 is about 5542.6894194064. The cubic root of 30721406 is about 313.1941892622.

The spelling of 30721406 in words is "thirty million, seven hundred twenty-one thousand, four hundred six".