1561346659 has 4 divisors (see below), whose sum is σ = 1561875160. Its totient is φ = 1560818160.

The previous prime is 1561346593. The next prime is 1561346671. The reversal of 1561346659 is 9566431651.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1561346659 - 2⁷ = 1561346531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1561346159) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 259794 + ... + 265735.

It is an arithmetic number, because the mean of its divisors is an integer number (390468790).

Almost surely, 2^1561346659 is an apocalyptic number.

1561346659 is a deficient number, since it is larger than the sum of its proper divisors (528501).

1561346659 is an equidigital number, since it uses as much as digits as its factorization.

1561346659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528500.

The product of its digits is 583200, while the sum is 46.

The square root of 1561346659 is about 39513.8793210689. The cubic root of 1561346659 is about 1160.1116269411. Note that the first 3 decimals are identical.

The spelling of 1561346659 in words is "one billion, five hundred sixty-one million, three hundred forty-six thousand, six hundred fifty-nine".