661768873 has 8 divisors (see below), whose sum is σ = 683776256. Its totient is φ = 639802800.

The previous prime is 661768847. The next prime is 661768967. The reversal of 661768873 is 378867166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 661768873 - 2²⁹ = 124897961 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 661768873.

It is not an unprimeable number, because it can be changed into a prime (661768813) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24118 + ... + 43648.

It is an arithmetic number, because the mean of its divisors is an integer number (85472032).

Almost surely, 2^661768873 is an apocalyptic number.

It is an amenable number.

661768873 is a deficient number, since it is larger than the sum of its proper divisors (22007383).

661768873 is a wasteful number, since it uses less digits than its factorization.

661768873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20655.

The product of its digits is 2032128, while the sum is 52.

The square root of 661768873 is about 25724.8687654573. The cubic root of 661768873 is about 871.4358958689.

The spelling of 661768873 in words is "six hundred sixty-one million, seven hundred sixty-eight thousand, eight hundred seventy-three".