21085113 has 8 divisors (see below), whose sum is σ = 32129728. Its totient is φ = 12048624.

The previous prime is 21085109. The next prime is 21085123. The reversal of 21085113 is 31158012.

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

It is not a de Polignac number, because 21085113 - 2² = 21085109 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 1004053 = 21085113 / (2 + 1 + 0 + 8 + 5 + 1 + 1 + 3).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21085113.

It is not an unprimeable number, because it can be changed into a prime (21085123) 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, 502006 + ... + 502047.

It is an arithmetic number, because the mean of its divisors is an integer number (4016216).

Almost surely, 2^21085113 is an apocalyptic number.

It is an amenable number.

21085113 is a deficient number, since it is larger than the sum of its proper divisors (11044615).

21085113 is a wasteful number, since it uses less digits than its factorization.

21085113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1004063.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 21085113 is about 4591.8528939852. The cubic root of 21085113 is about 276.2646458660.

The spelling of 21085113 in words is "twenty-one million, eighty-five thousand, one hundred thirteen".