21880560 has 80 divisors (see below), whose sum is σ = 73057824. Its totient is φ = 5385216.

The previous prime is 21880559. The next prime is 21880583. The reversal of 21880560 is 6508812.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 387 + ... + 6626.

Almost surely, 2^21880560 is an apocalyptic number.

21880560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21880560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36528912).

21880560 is an abundant number, since it is smaller than the sum of its proper divisors (51177264).

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

21880560 is a wasteful number, since it uses less digits than its factorization.

21880560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7042 (or 7036 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 21880560 is about 4677.6660847051. Note that the first 3 decimals coincide. The cubic root of 21880560 is about 279.6959284103.

The spelling of 21880560 in words is "twenty-one million, eight hundred eighty thousand, five hundred sixty".