561971801 has 4 divisors (see below), whose sum is σ = 562138932. Its totient is φ = 561804672.

The previous prime is 561971749. The next prime is 561971807. The reversal of 561971801 is 108179165.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 108179165 = 5 ⋅21635833.

It can be written as a sum of positive squares in 2 ways, for example, as 307090576 + 254881225 = 17524^2 + 15965^2 .

It is a cyclic number.

It is not a de Polignac number, because 561971801 - 2²⁶ = 494862937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561971807) 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, 78416 + ... + 85281.

It is an arithmetic number, because the mean of its divisors is an integer number (140534733).

Almost surely, 2^561971801 is an apocalyptic number.

It is an amenable number.

561971801 is a deficient number, since it is larger than the sum of its proper divisors (167131).

561971801 is a wasteful number, since it uses less digits than its factorization.

561971801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167130.

The product of its (nonzero) digits is 15120, while the sum is 38.

The square root of 561971801 is about 23705.9444232876. The cubic root of 561971801 is about 825.2233498736.

The spelling of 561971801 in words is "five hundred sixty-one million, nine hundred seventy-one thousand, eight hundred one".