661088276749 has 2 divisors, whose sum is σ = 661088276750. Its totient is φ = 661088276748.

The previous prime is 661088276609. The next prime is 661088276759. The reversal of 661088276749 is 947672880166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 588035917225 + 73052359524 = 766835^2 + 270282^2 .

It is a cyclic number.

It is not a de Polignac number, because 661088276749 - 2²⁷ = 660954059021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661088276759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330544138374 + 330544138375.

It is an arithmetic number, because the mean of its divisors is an integer number (330544138375).

Almost surely, 2^661088276749 is an apocalyptic number.

It is an amenable number.

661088276749 is a deficient number, since it is larger than the sum of its proper divisors (1).

661088276749 is an equidigital number, since it uses as much as digits as its factorization.

661088276749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48771072, while the sum is 64.

The spelling of 661088276749 in words is "six hundred sixty-one billion, eighty-eight million, two hundred seventy-six thousand, seven hundred forty-nine".