21110985 has 48 divisors (see below), whose sum is σ = 43280640. Its totient is φ = 9313920.

The previous prime is 21110981. The next prime is 21110989. The reversal of 21110985 is 58901112.

It is an interprime number because it is at equal distance from previous prime (21110981) and next prime (21110989).

It is not a de Polignac number, because 21110985 - 2² = 21110981 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21110981) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7980 + ... + 10290.

It is an arithmetic number, because the mean of its divisors is an integer number (901680).

Almost surely, 2^21110985 is an apocalyptic number.

It is an amenable number.

21110985 is an abundant number, since it is smaller than the sum of its proper divisors (22169655).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21110985 is a wasteful number, since it uses less digits than its factorization.

21110985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2358 (or 2355 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 21110985 is about 4594.6691937505. The cubic root of 21110985 is about 276.3775943953.

The spelling of 21110985 in words is "twenty-one million, one hundred ten thousand, nine hundred eighty-five".