21442760 has 16 divisors (see below), whose sum is σ = 48246300. Its totient is φ = 8577088.

The previous prime is 21442753. The next prime is 21442777. The reversal of 21442760 is 6724412.

It can be written as a sum of positive squares in 2 ways, for example, as 20921476 + 521284 = 4574^2 + 722^2 .

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, 267995 + ... + 268074.

Almost surely, 2^21442760 is an apocalyptic number.

21442760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21442760 is an abundant number, since it is smaller than the sum of its proper divisors (26803540).

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

21442760 is a wasteful number, since it uses less digits than its factorization.

21442760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536080 (or 536076 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 21442760 is about 4630.6327861319. The cubic root of 21442760 is about 277.8179025889.

The spelling of 21442760 in words is "twenty-one million, four hundred forty-two thousand, seven hundred sixty".