15968521687 has 2 divisors, whose sum is σ = 15968521688. Its totient is φ = 15968521686.

The previous prime is 15968521643. The next prime is 15968521703. The reversal of 15968521687 is 78612586951.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15968521687 - 2³¹ = 13821038039 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15968521607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7984260843 + 7984260844.

It is an arithmetic number, because the mean of its divisors is an integer number (7984260844).

Almost surely, 2^15968521687 is an apocalyptic number.

15968521687 is a deficient number, since it is larger than the sum of its proper divisors (1).

15968521687 is an equidigital number, since it uses as much as digits as its factorization.

15968521687 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7257600, while the sum is 58.

The spelling of 15968521687 in words is "fifteen billion, nine hundred sixty-eight million, five hundred twenty-one thousand, six hundred eighty-seven".