1561340173 has 2 divisors, whose sum is σ = 1561340174. Its totient is φ = 1561340172.

The previous prime is 1561340107. The next prime is 1561340177. The reversal of 1561340173 is 3710431651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1167793929 + 393546244 = 34173^2 + 19838^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561340173 - 2²⁹ = 1024469261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561340177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780670086 + 780670087.

It is an arithmetic number, because the mean of its divisors is an integer number (780670087).

Almost surely, 2^1561340173 is an apocalyptic number.

It is an amenable number.

1561340173 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561340173 is an equidigital number, since it uses as much as digits as its factorization.

1561340173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 1561340173 is about 39513.7972485561. The cubic root of 1561340173 is about 1160.1100205299.

The spelling of 1561340173 in words is "one billion, five hundred sixty-one million, three hundred forty thousand, one hundred seventy-three".