101980561 has 4 divisors (see below), whose sum is σ = 103126500. Its totient is φ = 100834624.

The previous prime is 101980507. The next prime is 101980577. The reversal of 101980561 is 165089101.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51840000 + 50140561 = 7200^2 + 7081^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-101980561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (101980591) 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, 572836 + ... + 573013.

It is an arithmetic number, because the mean of its divisors is an integer number (25781625).

Almost surely, 2^101980561 is an apocalyptic number.

It is an amenable number.

101980561 is a deficient number, since it is larger than the sum of its proper divisors (1145939).

101980561 is an equidigital number, since it uses as much as digits as its factorization.

101980561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1145938.

The product of its (nonzero) digits is 2160, while the sum is 31.

The square root of 101980561 is about 10098.5425186014. The cubic root of 101980561 is about 467.2031894471.

The spelling of 101980561 in words is "one hundred one million, nine hundred eighty thousand, five hundred sixty-one".