21776480 has 48 divisors (see below), whose sum is σ = 56128464. Its totient is φ = 7918080.

The previous prime is 21776479. The next prime is 21776497. The reversal of 21776480 is 8467712.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21776480.

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, 4427 + ... + 7946.

It is an arithmetic number, because the mean of its divisors is an integer number (1169343).

Almost surely, 2^21776480 is an apocalyptic number.

21776480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21776480 is an abundant number, since it is smaller than the sum of its proper divisors (34351984).

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

21776480 is a wasteful number, since it uses less digits than its factorization.

21776480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12399 (or 12391 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 21776480 is about 4666.5276169760. The cubic root of 21776480 is about 279.2517436795.

The spelling of 21776480 in words is "twenty-one million, seven hundred seventy-six thousand, four hundred eighty".