15993397 has 16 divisors (see below), whose sum is σ = 18703872. Its totient is φ = 13394160.

The previous prime is 15993391. The next prime is 15993401. The reversal of 15993397 is 79339951.

It is a cyclic number.

It is not a de Polignac number, because 15993397 - 2¹⁹ = 15469109 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 (15993391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 98038 + ... + 98200.

It is an arithmetic number, because the mean of its divisors is an integer number (1168992).

Almost surely, 2^15993397 is an apocalyptic number.

It is an amenable number.

15993397 is a deficient number, since it is larger than the sum of its proper divisors (2710475).

15993397 is a wasteful number, since it uses less digits than its factorization.

15993397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408.

The product of its digits is 229635, while the sum is 46.

The square root of 15993397 is about 3999.1745398269. The cubic root of 15993397 is about 251.9495416316.

The spelling of 15993397 in words is "fifteen million, nine hundred ninety-three thousand, three hundred ninety-seven".