101026561561 has 4 divisors (see below), whose sum is σ = 101140975312. Its totient is φ = 100912147812.

The previous prime is 101026561549. The next prime is 101026561613. The reversal of 101026561561 is 165165620101.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 101026561561 - 2⁵ = 101026561529 is a prime.

It is a super-2 number, since 2×101026561561² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (101026561501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57205551 + ... + 57207316.

It is an arithmetic number, because the mean of its divisors is an integer number (25285243828).

Almost surely, 2^101026561561 is an apocalyptic number.

It is an amenable number.

101026561561 is a deficient number, since it is larger than the sum of its proper divisors (114413751).

101026561561 is an equidigital number, since it uses as much as digits as its factorization.

101026561561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114413750.

The product of its (nonzero) digits is 10800, while the sum is 34.

The spelling of 101026561561 in words is "one hundred one billion, twenty-six million, five hundred sixty-one thousand, five hundred sixty-one".