21982549 has 8 divisors (see below), whose sum is σ = 23167872. Its totient is φ = 20816400.

The previous prime is 21982537. The next prime is 21982567. The reversal of 21982549 is 94528912.

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 21982549 - 2⁵ = 21982517 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 (21982579) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2409 + ... + 7054.

It is an arithmetic number, because the mean of its divisors is an integer number (2895984).

Almost surely, 2^21982549 is an apocalyptic number.

It is an amenable number.

21982549 is a deficient number, since it is larger than the sum of its proper divisors (1185323).

21982549 is a wasteful number, since it uses less digits than its factorization.

21982549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9587.

The product of its digits is 51840, while the sum is 40.

The square root of 21982549 is about 4688.5551079197. Note that the first 3 decimals coincide. The cubic root of 21982549 is about 280.1298250000.

The spelling of 21982549 in words is "twenty-one million, nine hundred eighty-two thousand, five hundred forty-nine".