30117921 has 16 divisors (see below), whose sum is σ = 41957760. Its totient is φ = 19192320.

The previous prime is 30117917. The next prime is 30117937. The reversal of 30117921 is 12971103.

It is not a de Polignac number, because 30117921 - 2² = 30117917 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 30117891 and 30117900.

It is not an unprimeable number, because it can be changed into a prime (30117721) 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, 7281 + ... + 10641.

It is an arithmetic number, because the mean of its divisors is an integer number (2622360).

Almost surely, 2^30117921 is an apocalyptic number.

It is an amenable number.

30117921 is a deficient number, since it is larger than the sum of its proper divisors (11839839).

30117921 is a wasteful number, since it uses less digits than its factorization.

30117921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3496.

The product of its (nonzero) digits is 378, while the sum is 24.

The square root of 30117921 is about 5487.9796829070. The cubic root of 30117921 is about 311.1298382954.

The spelling of 30117921 in words is "thirty million, one hundred seventeen thousand, nine hundred twenty-one".