661086277 has 2 divisors, whose sum is σ = 661086278. Its totient is φ = 661086276.

The previous prime is 661086271. The next prime is 661086317. The reversal of 661086277 is 772680166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 659513761 + 1572516 = 25681^2 + 1254^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661086277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661086271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330543138 + 330543139.

It is an arithmetic number, because the mean of its divisors is an integer number (330543139).

Almost surely, 2^661086277 is an apocalyptic number.

It is an amenable number.

661086277 is a deficient number, since it is larger than the sum of its proper divisors (1).

661086277 is an equidigital number, since it uses as much as digits as its factorization.

661086277 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 169344, while the sum is 43.

The square root of 661086277 is about 25711.5981028018. The cubic root of 661086277 is about 871.1361722453.

The spelling of 661086277 in words is "six hundred sixty-one million, eighty-six thousand, two hundred seventy-seven".