1560817121 has 2 divisors, whose sum is σ = 1560817122. Its totient is φ = 1560817120.

The previous prime is 1560817079. The next prime is 1560817123. The reversal of 1560817121 is 1217180651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1555434721 + 5382400 = 39439^2 + 2320^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1560817121 is a prime.

Together with 1560817123, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1560817123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780408560 + 780408561.

It is an arithmetic number, because the mean of its divisors is an integer number (780408561).

Almost surely, 2^1560817121 is an apocalyptic number.

It is an amenable number.

1560817121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1560817121 is an equidigital number, since it uses as much as digits as its factorization.

1560817121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 32.

The square root of 1560817121 is about 39507.1780946197. The cubic root of 1560817121 is about 1159.9804596887.

Adding to 1560817121 its reverse (1217180651), we get a palindrome (2777997772).

The spelling of 1560817121 in words is "one billion, five hundred sixty million, eight hundred seventeen thousand, one hundred twenty-one".