21980489 has 4 divisors (see below), whose sum is σ = 22308624. Its totient is φ = 21652356.

The previous prime is 21980467. The next prime is 21980513. The reversal of 21980489 is 98408912.

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 a de Polignac number, because none of the positive numbers 2^k-21980489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21980429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 163967 + ... + 164100.

It is an arithmetic number, because the mean of its divisors is an integer number (5577156).

Almost surely, 2^21980489 is an apocalyptic number.

It is an amenable number.

21980489 is a deficient number, since it is larger than the sum of its proper divisors (328135).

21980489 is an equidigital number, since it uses as much as digits as its factorization.

21980489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328134.

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 21980489 is about 4688.3354188880. The cubic root of 21980489 is about 280.1210743396.

It can be divided in two parts, 219 and 80489, that added together give a palindrome (80708).

The spelling of 21980489 in words is "twenty-one million, nine hundred eighty thousand, four hundred eighty-nine".