661184200477 has 2 divisors, whose sum is σ = 661184200478. Its totient is φ = 661184200476.

The previous prime is 661184200463. The next prime is 661184200487. The reversal of 661184200477 is 774002481166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 334470215556 + 326713984921 = 578334^2 + 571589^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661184200477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661184200487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330592100238 + 330592100239.

It is an arithmetic number, because the mean of its divisors is an integer number (330592100239).

Almost surely, 2^661184200477 is an apocalyptic number.

It is an amenable number.

661184200477 is a deficient number, since it is larger than the sum of its proper divisors (1).

661184200477 is an equidigital number, since it uses as much as digits as its factorization.

661184200477 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 451584, while the sum is 46.

The spelling of 661184200477 in words is "six hundred sixty-one billion, one hundred eighty-four million, two hundred thousand, four hundred seventy-seven".