661892377766 has 4 divisors (see below), whose sum is σ = 992838566652. Its totient is φ = 330946188882.

The previous prime is 661892377759. The next prime is 661892377777. The reversal of 661892377766 is 667773298166.

661892377766 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 661892377696 and 661892377705.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165473094440 + ... + 165473094443.

It is an arithmetic number, because the mean of its divisors is an integer number (248209641663).

Almost surely, 2^661892377766 is an apocalyptic number.

661892377766 is a deficient number, since it is larger than the sum of its proper divisors (330946188886).

661892377766 is a wasteful number, since it uses less digits than its factorization.

661892377766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330946188885.

The product of its digits is 192036096, while the sum is 68.

The spelling of 661892377766 in words is "six hundred sixty-one billion, eight hundred ninety-two million, three hundred seventy-seven thousand, seven hundred sixty-six".