19664708927 has 4 divisors (see below), whose sum is σ = 20144336016. Its totient is φ = 19185081840.

The previous prime is 19664708887. The next prime is 19664708941. The reversal of 19664708927 is 72980746691.

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 19664708927 - 2¹⁴ = 19664692543 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 (19664708527) 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, 239813483 + ... + 239813564.

It is an arithmetic number, because the mean of its divisors is an integer number (5036084004).

Almost surely, 2^19664708927 is an apocalyptic number.

19664708927 is a deficient number, since it is larger than the sum of its proper divisors (479627089).

19664708927 is an equidigital number, since it uses as much as digits as its factorization.

19664708927 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479627088.

The product of its (nonzero) digits is 9144576, while the sum is 59.

The spelling of 19664708927 in words is "nineteen billion, six hundred sixty-four million, seven hundred eight thousand, nine hundred twenty-seven".