21076765 has 16 divisors (see below), whose sum is σ = 26380080. Its totient is φ = 16145920.

The previous prime is 21076739. The next prime is 21076789. The reversal of 21076765 is 56767012.

It can be written as a sum of positive squares in 8 ways, for example, as 91204 + 20985561 = 302^2 + 4581^2 .

It is not a de Polignac number, because 21076765 - 2⁷ = 21076637 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 21076765.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19335 + ... + 20395.

It is an arithmetic number, because the mean of its divisors is an integer number (1648755).

Almost surely, 2^21076765 is an apocalyptic number.

It is an amenable number.

21076765 is a deficient number, since it is larger than the sum of its proper divisors (5303315).

21076765 is a wasteful number, since it uses less digits than its factorization.

21076765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1232.

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 21076765 is about 4590.9438027491. The cubic root of 21076765 is about 276.2281815654.

The spelling of 21076765 in words is "twenty-one million, seventy-six thousand, seven hundred sixty-five".