15556397 has 4 divisors (see below), whose sum is σ = 15630336. Its totient is φ = 15482460.

The previous prime is 15556393. The next prime is 15556423. The reversal of 15556397 is 79365551.

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 15556397 - 2² = 15556393 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 (15556393) 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, 36653 + ... + 37074.

It is an arithmetic number, because the mean of its divisors is an integer number (3907584).

Almost surely, 2^15556397 is an apocalyptic number.

It is an amenable number.

15556397 is a deficient number, since it is larger than the sum of its proper divisors (73939).

15556397 is an equidigital number, since it uses as much as digits as its factorization.

15556397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73938.

The product of its digits is 141750, while the sum is 41.

The square root of 15556397 is about 3944.1598598434. The cubic root of 15556397 is about 249.6335805428.

The spelling of 15556397 in words is "fifteen million, five hundred fifty-six thousand, three hundred ninety-seven".