21118713 has 16 divisors (see below), whose sum is σ = 35106816. Its totient is φ = 10970640.

The previous prime is 21118663. The next prime is 21118717. The reversal of 21118713 is 31781112.

It is a happy number.

It is not a de Polignac number, because 21118713 - 2²² = 16924409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21118717) 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, 45481 + ... + 45942.

It is an arithmetic number, because the mean of its divisors is an integer number (2194176).

Almost surely, 2^21118713 is an apocalyptic number.

It is an amenable number.

21118713 is a deficient number, since it is larger than the sum of its proper divisors (13988103).

21118713 is a wasteful number, since it uses less digits than its factorization.

21118713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91444.

The product of its digits is 336, while the sum is 24.

The square root of 21118713 is about 4595.5100913827. The cubic root of 21118713 is about 276.4113143675.

Adding to 21118713 its reverse (31781112), we get a palindrome (52899825).

The spelling of 21118713 in words is "twenty-one million, one hundred eighteen thousand, seven hundred thirteen".