21571713 has 12 divisors (see below), whose sum is σ = 31204368. Its totient is φ = 14360280.

The previous prime is 21571673. The next prime is 21571721. The reversal of 21571713 is 31717512.

It is a happy number.

21571713 is a `hidden beast` number, since 21 + 571 + 71 + 3 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-21571713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21571763) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7258 + ... + 9788.

It is an arithmetic number, because the mean of its divisors is an integer number (2600364).

Almost surely, 2^21571713 is an apocalyptic number.

It is an amenable number.

21571713 is a deficient number, since it is larger than the sum of its proper divisors (9632655).

21571713 is a wasteful number, since it uses less digits than its factorization.

21571713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3484 (or 3481 counting only the distinct ones).

The product of its digits is 1470, while the sum is 27.

The square root of 21571713 is about 4644.5358218018. The cubic root of 21571713 is about 278.3737059615.

The spelling of 21571713 in words is "twenty-one million, five hundred seventy-one thousand, seven hundred thirteen".