21949880 has 32 divisors (see below), whose sum is σ = 50725440. Its totient is φ = 8542080.

The previous prime is 21949877. The next prime is 21949927. The reversal of 21949880 is 8894912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5936 + ... + 8895.

It is an arithmetic number, because the mean of its divisors is an integer number (1585170).

Almost surely, 2^21949880 is an apocalyptic number.

21949880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21949880 is an abundant number, since it is smaller than the sum of its proper divisors (28775560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21949880 is a wasteful number, since it uses less digits than its factorization.

21949880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14879 (or 14875 counting only the distinct ones).

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

The square root of 21949880 is about 4685.0699034273. The cubic root of 21949880 is about 279.9909861044.

The spelling of 21949880 in words is "twenty-one million, nine hundred forty-nine thousand, eight hundred eighty".