673787991 has 8 divisors (see below), whose sum is σ = 898508160. Its totient is φ = 449129912.

The previous prime is 673787987. The next prime is 673787999. The reversal of 673787991 is 199787376.

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

It is a cyclic number.

It is not a de Polignac number, because 673787991 - 2² = 673787987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (673787999) 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, 24670 + ... + 44228.

It is an arithmetic number, because the mean of its divisors is an integer number (112313520).

Almost surely, 2^673787991 is an apocalyptic number.

673787991 is a deficient number, since it is larger than the sum of its proper divisors (224720169).

673787991 is a wasteful number, since it uses less digits than its factorization.

673787991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31045.

The product of its digits is 4000752, while the sum is 57.

The square root of 673787991 is about 25957.4265095753. The cubic root of 673787991 is about 876.6799793809.

The spelling of 673787991 in words is "six hundred seventy-three million, seven hundred eighty-seven thousand, nine hundred ninety-one".