21802859 has 6 divisors (see below), whose sum is σ = 23609196. Its totient is φ = 20125560.

The previous prime is 21802819. The next prime is 21802871. The reversal of 21802859 is 95820812.

It is a de Polignac number, because none of the positive numbers 2^k-21802859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21802819) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 64337 + ... + 64674.

It is an arithmetic number, because the mean of its divisors is an integer number (3934866).

Almost surely, 2^21802859 is an apocalyptic number.

21802859 is a deficient number, since it is larger than the sum of its proper divisors (1806337).

21802859 is a wasteful number, since it uses less digits than its factorization.

21802859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129037 (or 129024 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 21802859 is about 4669.3531671956. The cubic root of 21802859 is about 279.3644556409.

The spelling of 21802859 in words is "twenty-one million, eight hundred two thousand, eight hundred fifty-nine".