15556961 has 6 divisors (see below), whose sum is σ = 18096930. Its totient is φ = 13334496.

The previous prime is 15556951. The next prime is 15556969. The reversal of 15556961 is 16965551.

It is a happy number.

15556961 is digitally balanced in base 2 and base 8, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 13249600 + 2307361 = 3640^2 + 1519^2 .

It is not a de Polignac number, because 15556961 - 2⁶ = 15556897 is a prime.

It is a Duffinian number.

15556961 is strictly pandigital in base 8.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (15556969) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 158696 + ... + 158793.

It is an arithmetic number, because the mean of its divisors is an integer number (3016155).

Almost surely, 2^15556961 is an apocalyptic number.

It is an amenable number.

15556961 is a deficient number, since it is larger than the sum of its proper divisors (2539969).

15556961 is an equidigital number, since it uses as much as digits as its factorization.

15556961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317503 (or 317496 counting only the distinct ones).

The product of its digits is 40500, while the sum is 38.

The square root of 15556961 is about 3944.2313573116. The cubic root of 15556961 is about 249.6365973433.

The spelling of 15556961 in words is "fifteen million, five hundred fifty-six thousand, nine hundred sixty-one".