30121931 has 4 divisors (see below), whose sum is σ = 34425072. Its totient is φ = 25818792.

The previous prime is 30121907. The next prime is 30121951. The reversal of 30121931 is 13912103.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13912103 = 17 ⋅818359.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30121931 is a prime.

It is a super-2 number, since 2×30121931² = 1814661454337522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30121901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2151560 + ... + 2151573.

It is an arithmetic number, because the mean of its divisors is an integer number (8606268).

Almost surely, 2^30121931 is an apocalyptic number.

30121931 is a deficient number, since it is larger than the sum of its proper divisors (4303141).

30121931 is an equidigital number, since it uses as much as digits as its factorization.

30121931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4303140.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 30121931 is about 5488.3450146652. The cubic root of 30121931 is about 311.1436459692.

The spelling of 30121931 in words is "thirty million, one hundred twenty-one thousand, nine hundred thirty-one".