21713008907 has 4 divisors (see below), whose sum is σ = 21713461440. Its totient is φ = 21712556376.

The previous prime is 21713008901. The next prime is 21713008927. The reversal of 21713008907 is 70980031712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21713008907 - 2²⁰ = 21711960331 is a prime.

It is a super-2 number, since 2×21713008907² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21713008901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144428 + ... + 253545.

It is an arithmetic number, because the mean of its divisors is an integer number (5428365360).

Almost surely, 2^21713008907 is an apocalyptic number.

21713008907 is a deficient number, since it is larger than the sum of its proper divisors (452533).

21713008907 is an equidigital number, since it uses as much as digits as its factorization.

21713008907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452532.

The product of its (nonzero) digits is 21168, while the sum is 38.

The spelling of 21713008907 in words is "twenty-one billion, seven hundred thirteen million, eight thousand, nine hundred seven".