1517231561 has 2 divisors, whose sum is σ = 1517231562. Its totient is φ = 1517231560.

The previous prime is 1517231537. The next prime is 1517231563. The reversal of 1517231561 is 1651327151.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1342489600 + 174741961 = 36640^2 + 13219^2 .

It is a cyclic number.

It is not a de Polignac number, because 1517231561 - 2¹⁰ = 1517230537 is a prime.

It is a Sophie Germain prime.

Together with 1517231563, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1517231563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 758615780 + 758615781.

It is an arithmetic number, because the mean of its divisors is an integer number (758615781).

Almost surely, 2^1517231561 is an apocalyptic number.

It is an amenable number.

1517231561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1517231561 is an equidigital number, since it uses as much as digits as its factorization.

1517231561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6300, while the sum is 32.

The square root of 1517231561 is about 38951.6567170127. The cubic root of 1517231561 is about 1149.0809445972.

The spelling of 1517231561 in words is "one billion, five hundred seventeen million, two hundred thirty-one thousand, five hundred sixty-one".