15993391 has 2 divisors, whose sum is σ = 15993392. Its totient is φ = 15993390.

The previous prime is 15993323. The next prime is 15993401. The reversal of 15993391 is 19339951.

15993391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15993391 - 2¹¹ = 15991343 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15993191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7996695 + 7996696.

It is an arithmetic number, because the mean of its divisors is an integer number (7996696).

Almost surely, 2^15993391 is an apocalyptic number.

15993391 is a deficient number, since it is larger than the sum of its proper divisors (1).

15993391 is an equidigital number, since it uses as much as digits as its factorization.

15993391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32805, while the sum is 40.

The square root of 15993391 is about 3999.1737896721. The cubic root of 15993391 is about 251.9495101249.

It can be divided in two parts, 15993 and 391, that added together give a 14-th power (16384 = 2¹⁴).

The spelling of 15993391 in words is "fifteen million, nine hundred ninety-three thousand, three hundred ninety-one".