21980549 has 8 divisors (see below), whose sum is σ = 23184000. Its totient is φ = 20781792.

The previous prime is 21980513. The next prime is 21980561. The reversal of 21980549 is 94508912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21980549 - 2⁸ = 21980293 is a prime.

It is a super-3 number, since 3×21980549³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21980449) 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 7 ways as a sum of consecutive naturals, for example, 12857 + ... + 14465.

It is an arithmetic number, because the mean of its divisors is an integer number (2898000).

Almost surely, 2^21980549 is an apocalyptic number.

It is an amenable number.

21980549 is a deficient number, since it is larger than the sum of its proper divisors (1203451).

21980549 is a wasteful number, since it uses less digits than its factorization.

21980549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2347.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 21980549 is about 4688.3418177432. The cubic root of 21980549 is about 280.1213292209.

The spelling of 21980549 in words is "twenty-one million, nine hundred eighty thousand, five hundred forty-nine".