21802985 has 8 divisors (see below), whose sum is σ = 26364096. Its totient is φ = 17308720.

The previous prime is 21802961. The next prime is 21802987. The reversal of 21802985 is 58920812.

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

It is not a de Polignac number, because 21802985 - 2²² = 17608681 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21802987) 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, 15989 + ... + 17298.

It is an arithmetic number, because the mean of its divisors is an integer number (3295512).

Almost surely, 2^21802985 is an apocalyptic number.

It is an amenable number.

21802985 is a deficient number, since it is larger than the sum of its proper divisors (4561111).

21802985 is a wasteful number, since it uses less digits than its factorization.

21802985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33423.

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

The square root of 21802985 is about 4669.3666594090. The cubic root of 21802985 is about 279.3649937944.

The spelling of 21802985 in words is "twenty-one million, eight hundred two thousand, nine hundred eighty-five".