30745921 has 4 divisors (see below), whose sum is σ = 31167172. Its totient is φ = 30324672.

The previous prime is 30745919. The next prime is 30745937. The reversal of 30745921 is 12954703.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13771521 + 16974400 = 3711^2 + 4120^2 .

It is a cyclic number.

It is not a de Polignac number, because 30745921 - 2¹ = 30745919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30745901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210516 + ... + 210661.

It is an arithmetic number, because the mean of its divisors is an integer number (7791793).

Almost surely, 2^30745921 is an apocalyptic number.

It is an amenable number.

30745921 is a deficient number, since it is larger than the sum of its proper divisors (421251).

30745921 is an equidigital number, since it uses as much as digits as its factorization.

30745921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421250.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 30745921 is about 5544.9004499630. The cubic root of 30745921 is about 313.2774744497.

The spelling of 30745921 in words is "thirty million, seven hundred forty-five thousand, nine hundred twenty-one".