15005561 has 2 divisors, whose sum is σ = 15005562. Its totient is φ = 15005560.

The previous prime is 15005531. The next prime is 15005563. The reversal of 15005561 is 16550051.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11833600 + 3171961 = 3440^2 + 1781^2 .

It is a cyclic number.

It is not a de Polignac number, because 15005561 - 2¹⁰ = 15004537 is a prime.

It is a Sophie Germain prime.

Together with 15005563, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (15005563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7502780 + 7502781.

It is an arithmetic number, because the mean of its divisors is an integer number (7502781).

Almost surely, 2^15005561 is an apocalyptic number.

It is an amenable number.

15005561 is a deficient number, since it is larger than the sum of its proper divisors (1).

15005561 is an equidigital number, since it uses as much as digits as its factorization.

15005561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 750, while the sum is 23.

The square root of 15005561 is about 3873.7012016933. The cubic root of 15005561 is about 246.6516805683.

The spelling of 15005561 in words is "fifteen million, five thousand, five hundred sixty-one".