21560766 has 16 divisors (see below), whose sum is σ = 43452288. Its totient is φ = 7131800.

The previous prime is 21560719. The next prime is 21560767. The reversal of 21560766 is 66706512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21560767) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12930 + ... + 14501.

It is an arithmetic number, because the mean of its divisors is an integer number (2715768).

Almost surely, 2^21560766 is an apocalyptic number.

21560766 is an abundant number, since it is smaller than the sum of its proper divisors (21891522).

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

21560766 is a wasteful number, since it uses less digits than its factorization.

21560766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27567.

The product of its (nonzero) digits is 15120, while the sum is 33.

The square root of 21560766 is about 4643.3571906542. The cubic root of 21560766 is about 278.3266092136.

The spelling of 21560766 in words is "twenty-one million, five hundred sixty thousand, seven hundred sixty-six".