21149613 has 16 divisors (see below), whose sum is σ = 32414400. Its totient is φ = 13613040.

The previous prime is 21149599. The next prime is 21149617. The reversal of 21149613 is 31694112.

21149613 is a `hidden beast` number, since 2 + 1 + 1 + 49 + 613 = 666.

It is not a de Polignac number, because 21149613 - 2⁶ = 21149549 is a prime.

It is a super-2 number, since 2×21149613² = 894612260099538, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21149617) 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, 12723 + ... + 14288.

It is an arithmetic number, because the mean of its divisors is an integer number (2025900).

Almost surely, 2^21149613 is an apocalyptic number.

It is an amenable number.

21149613 is a deficient number, since it is larger than the sum of its proper divisors (11264787).

21149613 is a wasteful number, since it uses less digits than its factorization.

21149613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27049 (or 27043 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 21149613 is about 4598.8708396736. The cubic root of 21149613 is about 276.5460597524.

The spelling of 21149613 in words is "twenty-one million, one hundred forty-nine thousand, six hundred thirteen".