30481921 has 4 divisors (see below), whose sum is σ = 30608644. Its totient is φ = 30355200.

The previous prime is 30481907. The next prime is 30481931. The reversal of 30481921 is 12918403.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12918403 = 41 ⋅315083.

It can be written as a sum of positive squares in 2 ways, for example, as 13957696 + 16524225 = 3736^2 + 4065^2 .

It is a cyclic number.

It is not a de Polignac number, because 30481921 - 2⁷ = 30481793 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 30481921.

It is not an unprimeable number, because it can be changed into a prime (30481931) 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, 63000 + ... + 63481.

It is an arithmetic number, because the mean of its divisors is an integer number (7652161).

Almost surely, 2^30481921 is an apocalyptic number.

It is an amenable number.

30481921 is a deficient number, since it is larger than the sum of its proper divisors (126723).

30481921 is a wasteful number, since it uses less digits than its factorization.

30481921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126722.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 30481921 is about 5521.0434702147. The cubic root of 30481921 is about 312.3782429135.

The spelling of 30481921 in words is "thirty million, four hundred eighty-one thousand, nine hundred twenty-one".