1561347373 has 2 divisors, whose sum is σ = 1561347374. Its totient is φ = 1561347372.

The previous prime is 1561347343. The next prime is 1561347377. The reversal of 1561347373 is 3737431651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1108423849 + 452923524 = 33293^2 + 21282^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1561347373 is a prime.

It is a super-2 number, since 2×1561347373² = 4875611238348002258, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561347377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780673686 + 780673687.

It is an arithmetic number, because the mean of its divisors is an integer number (780673687).

Almost surely, 2^1561347373 is an apocalyptic number.

It is an amenable number.

1561347373 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561347373 is an equidigital number, since it uses as much as digits as its factorization.

1561347373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 158760, while the sum is 40.

The square root of 1561347373 is about 39513.8883558680. Note that the first 3 decimals coincide. The cubic root of 1561347373 is about 1160.1118037798. Note that the first 3 decimals are identical.

The spelling of 1561347373 in words is "one billion, five hundred sixty-one million, three hundred forty-seven thousand, three hundred seventy-three".