15556889 has 2 divisors, whose sum is σ = 15556890. Its totient is φ = 15556888.

The previous prime is 15556873. The next prime is 15556897. The reversal of 15556889 is 98865551.

15556889 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 can be written as a sum of positive squares in only one way, i.e., 9406489 + 6150400 = 3067^2 + 2480^2 .

It is a cyclic number.

It is not a de Polignac number, because 15556889 - 2⁴ = 15556873 is a prime.

It is a plaindrome in base 10.

It is not a weakly prime, because it can be changed into another prime (15556829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7778444 + 7778445.

It is an arithmetic number, because the mean of its divisors is an integer number (7778445).

Almost surely, 2^15556889 is an apocalyptic number.

It is an amenable number.

15556889 is a deficient number, since it is larger than the sum of its proper divisors (1).

15556889 is an equidigital number, since it uses as much as digits as its factorization.

15556889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432000, while the sum is 47.

The square root of 15556889 is about 3944.2222300474. Note that the first 4 decimals coincide. The cubic root of 15556889 is about 249.6362122239.

The spelling of 15556889 in words is "fifteen million, five hundred fifty-six thousand, eight hundred eighty-nine".