1561701611 has 2 divisors, whose sum is σ = 1561701612. Its totient is φ = 1561701610.

The previous prime is 1561701461. The next prime is 1561701613. The reversal of 1561701611 is 1161071651.

It is a strong prime.

It is an emirp because it is prime and its reverse (1161071651) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1561701611 is a prime.

It is a Sophie Germain prime.

Together with 1561701613, 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 (1561701613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780850805 + 780850806.

It is an arithmetic number, because the mean of its divisors is an integer number (780850806).

Almost surely, 2^1561701611 is an apocalyptic number.

1561701611 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561701611 is an equidigital number, since it uses as much as digits as its factorization.

1561701611 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 29.

The square root of 1561701611 is about 39518.3705509223. The cubic root of 1561701611 is about 1160.1995324124.

The spelling of 1561701611 in words is "one billion, five hundred sixty-one million, seven hundred one thousand, six hundred eleven".