30684921 has 16 divisors (see below), whose sum is σ = 42837120. Its totient is φ = 19500800.

The previous prime is 30684889. The next prime is 30684959. The reversal of 30684921 is 12948603.

It is a cyclic number.

It is not a de Polignac number, because 30684921 - 2⁵ = 30684889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (30684961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27115 + ... + 28223.

It is an arithmetic number, because the mean of its divisors is an integer number (2677320).

Almost surely, 2^30684921 is an apocalyptic number.

It is an amenable number.

30684921 is a deficient number, since it is larger than the sum of its proper divisors (12152199).

30684921 is a wasteful number, since it uses less digits than its factorization.

30684921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1536.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 30684921 is about 5539.3971693678. The cubic root of 30684921 is about 313.0701561310.

The spelling of 30684921 in words is "thirty million, six hundred eighty-four thousand, nine hundred twenty-one".