15664381693 has 4 divisors (see below), whose sum is σ = 15671976768. Its totient is φ = 15656786620.

The previous prime is 15664381669. The next prime is 15664381703. The reversal of 15664381693 is 39618346651.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 39618346651 = 13 ⋅3047565127.

It is a cyclic number.

It is not a de Polignac number, because 15664381693 - 2⁹ = 15664381181 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15664381693.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15664381643) 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, 3794443 + ... + 3798568.

It is an arithmetic number, because the mean of its divisors is an integer number (3917994192).

Almost surely, 2^15664381693 is an apocalyptic number.

It is an amenable number.

15664381693 is a deficient number, since it is larger than the sum of its proper divisors (7595075).

15664381693 is an equidigital number, since it uses as much as digits as its factorization.

15664381693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7595074.

The product of its digits is 2799360, while the sum is 52.

The spelling of 15664381693 in words is "fifteen billion, six hundred sixty-four million, three hundred eighty-one thousand, six hundred ninety-three".