1561344539 has 2 divisors, whose sum is σ = 1561344540. Its totient is φ = 1561344538.

The previous prime is 1561344523. The next prime is 1561344541. The reversal of 1561344539 is 9354431651.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1561344539 - 2⁴ = 1561344523 is a prime.

Together with 1561344541, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1561344496 and 1561344505.

It is not a weakly prime, because it can be changed into another prime (1561344839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780672269 + 780672270.

It is an arithmetic number, because the mean of its divisors is an integer number (780672270).

Almost surely, 2^1561344539 is an apocalyptic number.

1561344539 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561344539 is an equidigital number, since it uses as much as digits as its factorization.

1561344539 is an evil number, because the sum of its binary digits is even.

The product of its digits is 194400, while the sum is 41.

The square root of 1561344539 is about 39513.8524950428. The cubic root of 1561344539 is about 1160.1111018735. Note that the first 4 decimals are identical.

The spelling of 1561344539 in words is "one billion, five hundred sixty-one million, three hundred forty-four thousand, five hundred thirty-nine".