15502561 has 2 divisors, whose sum is σ = 15502562. Its totient is φ = 15502560.

The previous prime is 15502549. The next prime is 15502567. The reversal of 15502561 is 16520551.

15502561 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., 15366400 + 136161 = 3920^2 + 369^2 .

It is a cyclic number.

It is not a de Polignac number, because 15502561 - 2⁹ = 15502049 is a prime.

It is not a weakly prime, because it can be changed into another prime (15502567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7751280 + 7751281.

It is an arithmetic number, because the mean of its divisors is an integer number (7751281).

Almost surely, 2^15502561 is an apocalyptic number.

It is an amenable number.

15502561 is a deficient number, since it is larger than the sum of its proper divisors (1).

15502561 is an equidigital number, since it uses as much as digits as its factorization.

15502561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 15502561 is about 3937.3291708974. The cubic root of 15502561 is about 249.3452788577.

The spelling of 15502561 in words is "fifteen million, five hundred two thousand, five hundred sixty-one".