1561234771 has 2 divisors, whose sum is σ = 1561234772. Its totient is φ = 1561234770.

The previous prime is 1561234739. The next prime is 1561234783. The reversal of 1561234771 is 1774321651.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1561234771 - 2⁵ = 1561234739 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1561234771.

It is not a weakly prime, because it can be changed into another prime (1561234471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780617385 + 780617386.

It is an arithmetic number, because the mean of its divisors is an integer number (780617386).

Almost surely, 2^1561234771 is an apocalyptic number.

1561234771 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561234771 is an equidigital number, since it uses as much as digits as its factorization.

1561234771 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35280, while the sum is 37.

The square root of 1561234771 is about 39512.4634893852. The cubic root of 1561234771 is about 1160.0839146092.

The spelling of 1561234771 in words is "one billion, five hundred sixty-one million, two hundred thirty-four thousand, seven hundred seventy-one".