67871991 has 8 divisors (see below), whose sum is σ = 98722944. Its totient is φ = 41134520.

The previous prime is 67871963. The next prime is 67872001. The reversal of 67871991 is 19917876.

It is a happy number.

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 67871991 - 2¹⁰ = 67870967 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 67871991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67871911) 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, 1028331 + ... + 1028396.

It is an arithmetic number, because the mean of its divisors is an integer number (12340368).

Almost surely, 2^67871991 is an apocalyptic number.

67871991 is a deficient number, since it is larger than the sum of its proper divisors (30850953).

67871991 is a wasteful number, since it uses less digits than its factorization.

67871991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2056741.

The product of its digits is 190512, while the sum is 48.

The square root of 67871991 is about 8238.4459092720. The cubic root of 67871991 is about 407.9092274514.

It can be divided in two parts, 6787 and 1991, that added together give a palindrome (8778).

The spelling of 67871991 in words is "sixty-seven million, eight hundred seventy-one thousand, nine hundred ninety-one".