21487713 has 16 divisors (see below), whose sum is σ = 31690176. Its totient is φ = 12864960.

The previous prime is 21487709. The next prime is 21487717. The reversal of 21487713 is 31778412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21487709) and next prime (21487717).

It is not a de Polignac number, because 21487713 - 2² = 21487709 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21487717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6003 + ... + 8888.

It is an arithmetic number, because the mean of its divisors is an integer number (1980636).

Almost surely, 2^21487713 is an apocalyptic number.

It is an amenable number.

21487713 is a deficient number, since it is larger than the sum of its proper divisors (10202463).

21487713 is a wasteful number, since it uses less digits than its factorization.

21487713 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14944.

The product of its digits is 9408, while the sum is 33.

The square root of 21487713 is about 4635.4841171123. The cubic root of 21487713 is about 278.0119079488.

The spelling of 21487713 in words is "twenty-one million, four hundred eighty-seven thousand, seven hundred thirteen".