105515561 has 2 divisors, whose sum is σ = 105515562. Its totient is φ = 105515560.

The previous prime is 105515551. The next prime is 105515567. The reversal of 105515561 is 165515501.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 103938025 + 1577536 = 10195^2 + 1256^2 .

It is a cyclic number.

It is not a de Polignac number, because 105515561 - 2⁶ = 105515497 is a prime.

It is a super-2 number, since 2×105515561² = 22267067226289442, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (105515567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52757780 + 52757781.

It is an arithmetic number, because the mean of its divisors is an integer number (52757781).

Almost surely, 2^105515561 is an apocalyptic number.

It is an amenable number.

105515561 is a deficient number, since it is larger than the sum of its proper divisors (1).

105515561 is an equidigital number, since it uses as much as digits as its factorization.

105515561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3750, while the sum is 29.

The square root of 105515561 is about 10272.0767617848. The cubic root of 105515561 is about 472.5402834182.

The spelling of 105515561 in words is "one hundred five million, five hundred fifteen thousand, five hundred sixty-one".