21145113 has 18 divisors (see below), whose sum is σ = 33573722. Its totient is φ = 12814560.

The previous prime is 21145109. The next prime is 21145141. The reversal of 21145113 is 31154112.

21145113 is a `hidden beast` number, since 211 + 451 + 1 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11108889 + 10036224 = 3333^2 + 3168^2 .

It is not a de Polignac number, because 21145113 - 2² = 21145109 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21145183) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 8620 + ... + 10797.

Almost surely, 2^21145113 is an apocalyptic number.

It is an amenable number.

21145113 is a deficient number, since it is larger than the sum of its proper divisors (12428609).

21145113 is a wasteful number, since it uses less digits than its factorization.

21145113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19445 (or 19431 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 21145113 is about 4598.3815631154. The cubic root of 21145113 is about 276.5264448066.

Adding to 21145113 its reverse (31154112), we get a palindrome (52299225).

It can be divided in two parts, 2114 and 5113, that added together give a palindrome (7227).

The spelling of 21145113 in words is "twenty-one million, one hundred forty-five thousand, one hundred thirteen".