538871991 has 32 divisors (see below), whose sum is σ = 861926400. Its totient is φ = 292790784.

The previous prime is 538871989. The next prime is 538871999. The reversal of 538871991 is 199178835.

It is not a de Polignac number, because 538871991 - 2¹ = 538871989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (538871999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 80335 + ... + 86783.

It is an arithmetic number, because the mean of its divisors is an integer number (26935200).

Almost surely, 2^538871991 is an apocalyptic number.

538871991 is a deficient number, since it is larger than the sum of its proper divisors (323054409).

538871991 is a wasteful number, since it uses less digits than its factorization.

538871991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6655.

The product of its digits is 544320, while the sum is 51.

The square root of 538871991 is about 23213.6164998046. The cubic root of 538871991 is about 813.7578735013.

The spelling of 538871991 in words is "five hundred thirty-eight million, eight hundred seventy-one thousand, nine hundred ninety-one".