101561 has 2 divisors, whose sum is σ = 101562. Its totient is φ = 101560.

The previous prime is 101537. The next prime is 101573. The reversal of 101561 is 165101.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59536 + 42025 = 244^2 + 205^2 .

It is a cyclic number.

It is not a de Polignac number, because 101561 - 2¹⁰ = 100537 is a prime.

It is not a weakly prime, because it can be changed into another prime (101501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50780 + 50781.

It is an arithmetic number, because the mean of its divisors is an integer number (50781).

2¹⁰¹⁵⁶¹ is an apocalyptic number.

It is an amenable number.

101561 is a deficient number, since it is larger than the sum of its proper divisors (1).

101561 is an equidigital number, since it uses as much as digits as its factorization.

101561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30, while the sum is 14.

The square root of 101561 is about 318.6863661972. The cubic root of 101561 is about 46.6561597661.

Adding to 101561 its reverse (165101), we get a palindrome (266662).

The spelling of 101561 in words is "one hundred one thousand, five hundred sixty-one".