680663087661 has 4 divisors (see below), whose sum is σ = 907550783552. Its totient is φ = 453775391772.

The previous prime is 680663087659. The next prime is 680663087717. The reversal of 680663087661 is 166780366086.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 680663087661 - 2¹ = 680663087659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (680663037661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113443847941 + ... + 113443847946.

It is an arithmetic number, because the mean of its divisors is an integer number (226887695888).

Almost surely, 2^680663087661 is an apocalyptic number.

It is an amenable number.

680663087661 is a deficient number, since it is larger than the sum of its proper divisors (226887695891).

680663087661 is a wasteful number, since it uses less digits than its factorization.

680663087661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226887695890.

The product of its (nonzero) digits is 10450944, while the sum is 57.

The spelling of 680663087661 in words is "six hundred eighty billion, six hundred sixty-three million, eighty-seven thousand, six hundred sixty-one".