1561651349 has 2 divisors, whose sum is σ = 1561651350. Its totient is φ = 1561651348.

The previous prime is 1561651303. The next prime is 1561651361. The reversal of 1561651349 is 9431561651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 882684100 + 678967249 = 29710^2 + 26057^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561651349 - 2²⁸ = 1293215893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561651379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780825674 + 780825675.

It is an arithmetic number, because the mean of its divisors is an integer number (780825675).

Almost surely, 2^1561651349 is an apocalyptic number.

It is an amenable number.

1561651349 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561651349 is an equidigital number, since it uses as much as digits as its factorization.

1561651349 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 97200, while the sum is 41.

The square root of 1561651349 is about 39517.7346137149. The cubic root of 1561651349 is about 1160.1870856099.

The spelling of 1561651349 in words is "one billion, five hundred sixty-one million, six hundred fifty-one thousand, three hundred forty-nine".