21796985 has 16 divisors (see below), whose sum is σ = 31193856. Its totient is φ = 14296128.

The previous prime is 21796981. The next prime is 21797003. The reversal of 21796985 is 58969712.

21796985 = 285² + 286² + ... + 445².

It is not a de Polignac number, because 21796985 - 2² = 21796981 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 (21796981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12734 + ... + 14343.

It is an arithmetic number, because the mean of its divisors is an integer number (1949616).

Almost surely, 2^21796985 is an apocalyptic number.

It is an amenable number.

21796985 is a deficient number, since it is larger than the sum of its proper divisors (9396871).

21796985 is a wasteful number, since it uses less digits than its factorization.

21796985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27112.

The product of its digits is 272160, while the sum is 47.

The square root of 21796985 is about 4668.7241297811. The cubic root of 21796985 is about 279.3393651363.

The spelling of 21796985 in words is "twenty-one million, seven hundred ninety-six thousand, nine hundred eighty-five".