21294880 has 48 divisors (see below), whose sum is σ = 53275320. Its totient is φ = 8015872.

The previous prime is 21294859. The next prime is 21294881. The reversal of 21294880 is 8849212.

It can be written as a sum of positive squares in 4 ways, for example, as 15968016 + 5326864 = 3996^2 + 2308^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (21294881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1195 + ... + 6634.

Almost surely, 2^21294880 is an apocalyptic number.

21294880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21294880 is an abundant number, since it is smaller than the sum of its proper divisors (31980440).

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

21294880 is a wasteful number, since it uses less digits than its factorization.

21294880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7861 (or 7853 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 21294880 is about 4614.6375805690. The cubic root of 21294880 is about 277.1777716920.

The spelling of 21294880 in words is "twenty-one million, two hundred ninety-four thousand, eight hundred eighty".