21123575717 has 8 divisors (see below), whose sum is σ = 22281772800. Its totient is φ = 19970021664.

The previous prime is 21123575701. The next prime is 21123575729. The reversal of 21123575717 is 71757532112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21123575717 - 2⁴ = 21123575701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123575917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1151408 + ... + 1169609.

It is an arithmetic number, because the mean of its divisors is an integer number (2785221600).

Almost surely, 2^21123575717 is an apocalyptic number.

It is an amenable number.

21123575717 is a deficient number, since it is larger than the sum of its proper divisors (1158197083).

21123575717 is a wasteful number, since it uses less digits than its factorization.

21123575717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2321515.

The product of its digits is 102900, while the sum is 41.

The spelling of 21123575717 in words is "twenty-one billion, one hundred twenty-three million, five hundred seventy-five thousand, seven hundred seventeen".