668880861 has 48 divisors (see below), whose sum is σ = 1048686912. Its totient is φ = 377597440.

The previous prime is 668880841. The next prime is 668880887. The reversal of 668880861 is 168088866.

It is a happy number.

It is not a de Polignac number, because 668880861 - 2¹⁴ = 668864477 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668880841) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 659791 + ... + 660803.

It is an arithmetic number, because the mean of its divisors is an integer number (21847644).

Almost surely, 2^668880861 is an apocalyptic number.

It is an amenable number.

668880861 is a deficient number, since it is larger than the sum of its proper divisors (379806051).

668880861 is a wasteful number, since it uses less digits than its factorization.

668880861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1162 (or 1151 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 51.

The square root of 668880861 is about 25862.7311202819. The cubic root of 668880861 is about 874.5465344487.

The spelling of 668880861 in words is "six hundred sixty-eight million, eight hundred eighty thousand, eight hundred sixty-one".