1561189243 has 2 divisors, whose sum is σ = 1561189244. Its totient is φ = 1561189242.

The previous prime is 1561189229. The next prime is 1561189291. The reversal of 1561189243 is 3429811651.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1561189243 - 2¹⁷ = 1561058171 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1561189196 and 1561189205.

It is not a weakly prime, because it can be changed into another prime (1561189213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780594621 + 780594622.

It is an arithmetic number, because the mean of its divisors is an integer number (780594622).

Almost surely, 2^1561189243 is an apocalyptic number.

1561189243 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561189243 is an equidigital number, since it uses as much as digits as its factorization.

1561189243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 40.

The square root of 1561189243 is about 39511.8873631721. The cubic root of 1561189243 is about 1160.0726378910.

The spelling of 1561189243 in words is "one billion, five hundred sixty-one million, one hundred eighty-nine thousand, two hundred forty-three".