30920621 has 4 divisors (see below), whose sum is σ = 30966972. Its totient is φ = 30874272.

The previous prime is 30920599. The next prime is 30920623. The reversal of 30920621 is 12602903.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12602903 = 37 ⋅340619.

It can be written as a sum of positive squares in 2 ways, for example, as 30085225 + 835396 = 5485^2 + 914^2 .

It is a cyclic number.

It is not a de Polignac number, because 30920621 - 2¹⁸ = 30658477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30920623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22160 + ... + 23513.

It is an arithmetic number, because the mean of its divisors is an integer number (7741743).

Almost surely, 2^30920621 is an apocalyptic number.

It is an amenable number.

30920621 is a deficient number, since it is larger than the sum of its proper divisors (46351).

30920621 is an equidigital number, since it uses as much as digits as its factorization.

30920621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46350.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 30920621 is about 5560.6313490466. The cubic root of 30920621 is about 313.8697073940.

The spelling of 30920621 in words is "thirty million, nine hundred twenty thousand, six hundred twenty-one".