21454880 has 24 divisors (see below), whose sum is σ = 50687532. Its totient is φ = 8581888.

The previous prime is 21454879. The next prime is 21454897. The reversal of 21454880 is 8845412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21196816 + 258064 = 4604^2 + 508^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66887 + ... + 67206.

Almost surely, 2^21454880 is an apocalyptic number.

21454880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21454880 is an abundant number, since it is smaller than the sum of its proper divisors (29232652).

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

21454880 is a wasteful number, since it uses less digits than its factorization.

21454880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134108 (or 134100 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 32.

The square root of 21454880 is about 4631.9412776934. The cubic root of 21454880 is about 277.8702360071.

It can be divided in two parts, 2145 and 4880, that multiplied together give a triangular number (10467600 = T₄₅₇₅).

The spelling of 21454880 in words is "twenty-one million, four hundred fifty-four thousand, eight hundred eighty".