632871991 has 4 divisors (see below), whose sum is σ = 635207584. Its totient is φ = 630536400.

The previous prime is 632871983. The next prime is 632871997. The reversal of 632871991 is 199178236.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 632871991 - 2³ = 632871983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (632871997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1167390 + ... + 1167931.

It is an arithmetic number, because the mean of its divisors is an integer number (158801896).

Almost surely, 2^632871991 is an apocalyptic number.

632871991 is a deficient number, since it is larger than the sum of its proper divisors (2335593).

632871991 is a wasteful number, since it uses less digits than its factorization.

632871991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2335592.

The product of its digits is 163296, while the sum is 46.

The square root of 632871991 is about 25156.9471717059. The cubic root of 632871991 is about 858.5625848527.

The spelling of 632871991 in words is "six hundred thirty-two million, eight hundred seventy-one thousand, nine hundred ninety-one".