21903769 has 8 divisors (see below), whose sum is σ = 23423688. Its totient is φ = 20409600.

The previous prime is 21903737. The next prime is 21903779. The reversal of 21903769 is 96730912.

It can be written as a sum of positive squares in 4 ways, for example, as 12873744 + 9030025 = 3588^2 + 3005^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21903769 - 2⁵ = 21903737 is a prime.

It is a super-2 number, since 2×21903769² = 959550192810722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21903709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4662 + ... + 8095.

It is an arithmetic number, because the mean of its divisors is an integer number (2927961).

Almost surely, 2^21903769 is an apocalyptic number.

It is an amenable number.

21903769 is a deficient number, since it is larger than the sum of its proper divisors (1519919).

21903769 is a wasteful number, since it uses less digits than its factorization.

21903769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12875.

The product of its (nonzero) digits is 20412, while the sum is 37.

The square root of 21903769 is about 4680.1462583983. The cubic root of 21903769 is about 279.7947858582.

The spelling of 21903769 in words is "twenty-one million, nine hundred three thousand, seven hundred sixty-nine".