15938718649 has 4 divisors (see below), whose sum is σ = 18215678464. Its totient is φ = 13661758836.

The previous prime is 15938718619. The next prime is 15938718701. The reversal of 15938718649 is 94681783951.

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.

It is a cyclic number.

It is not a de Polignac number, because 15938718649 - 2²³ = 15930330041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15938718619) 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, 1138479897 + ... + 1138479910.

It is an arithmetic number, because the mean of its divisors is an integer number (4553919616).

Almost surely, 2^15938718649 is an apocalyptic number.

It is an amenable number.

15938718649 is a deficient number, since it is larger than the sum of its proper divisors (2276959815).

15938718649 is an equidigital number, since it uses as much as digits as its factorization.

15938718649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2276959814.

The product of its digits is 13063680, while the sum is 61.

The spelling of 15938718649 in words is "fifteen billion, nine hundred thirty-eight million, seven hundred eighteen thousand, six hundred forty-nine".