21980481 has 4 divisors (see below), whose sum is σ = 29307312. Its totient is φ = 14653652.

The previous prime is 21980467. The next prime is 21980513. The reversal of 21980481 is 18408912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21980481 - 2⁵ = 21980449 is a prime.

It is a super-2 number, since 2×21980481² = 966283089982722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21980401) 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, 3663411 + ... + 3663416.

It is an arithmetic number, because the mean of its divisors is an integer number (7326828).

Almost surely, 2^21980481 is an apocalyptic number.

It is an amenable number.

21980481 is a deficient number, since it is larger than the sum of its proper divisors (7326831).

21980481 is an equidigital number, since it uses as much as digits as its factorization.

21980481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7326830.

The product of its (nonzero) digits is 4608, while the sum is 33.

The square root of 21980481 is about 4688.3345657067. The cubic root of 21980481 is about 280.1210403554.

The spelling of 21980481 in words is "twenty-one million, nine hundred eighty thousand, four hundred eighty-one".