731988891 has 6 divisors (see below), whose sum is σ = 1057317300. Its totient is φ = 487992588.

The previous prime is 731988853. The next prime is 731988893. The reversal of 731988891 is 198889137.

731988891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 731988891 - 2⁹ = 731988379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (731988893) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 40666041 + ... + 40666058.

It is an arithmetic number, because the mean of its divisors is an integer number (176219550).

Almost surely, 2^731988891 is an apocalyptic number.

731988891 is a deficient number, since it is larger than the sum of its proper divisors (325328409).

731988891 is a wasteful number, since it uses less digits than its factorization.

731988891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81332105 (or 81332102 counting only the distinct ones).

The product of its digits is 870912, while the sum is 54.

The square root of 731988891 is about 27055.2932159310. The cubic root of 731988891 is about 901.2283191249.

The spelling of 731988891 in words is "seven hundred thirty-one million, nine hundred eighty-eight thousand, eight hundred ninety-one".