75115561 has 2 divisors, whose sum is σ = 75115562. Its totient is φ = 75115560.

The previous prime is 75115553. The next prime is 75115627. The reversal of 75115561 is 16551157.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74926336 + 189225 = 8656^2 + 435^2 .

It is a cyclic number.

It is not a de Polignac number, because 75115561 - 2³ = 75115553 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (75115501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37557780 + 37557781.

It is an arithmetic number, because the mean of its divisors is an integer number (37557781).

Almost surely, 2^75115561 is an apocalyptic number.

It is an amenable number.

75115561 is a deficient number, since it is larger than the sum of its proper divisors (1).

75115561 is an equidigital number, since it uses as much as digits as its factorization.

75115561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5250, while the sum is 31.

The square root of 75115561 is about 8666.9233872234. The cubic root of 75115561 is about 421.9328168844.

The spelling of 75115561 in words is "seventy-five million, one hundred fifteen thousand, five hundred sixty-one".