661185275759 has 2 divisors, whose sum is σ = 661185275760. Its totient is φ = 661185275758.

The previous prime is 661185275683. The next prime is 661185275761. The reversal of 661185275759 is 957572581166.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661185275759 is a prime.

Together with 661185275761, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661185275459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330592637879 + 330592637880.

It is an arithmetic number, because the mean of its divisors is an integer number (330592637880).

Almost surely, 2^661185275759 is an apocalyptic number.

661185275759 is a deficient number, since it is larger than the sum of its proper divisors (1).

661185275759 is an equidigital number, since it uses as much as digits as its factorization.

661185275759 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31752000, while the sum is 62.

The spelling of 661185275759 in words is "six hundred sixty-one billion, one hundred eighty-five million, two hundred seventy-five thousand, seven hundred fifty-nine".