671099991 has 16 divisors (see below), whose sum is σ = 929832960. Its totient is φ = 430022880.

The previous prime is 671099977. The next prime is 671100019. The reversal of 671099991 is 199990176.

It is not a de Polignac number, because 671099991 - 2¹⁵ = 671067223 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671099921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2106 + ... + 36696.

It is an arithmetic number, because the mean of its divisors is an integer number (58114560).

Almost surely, 2^671099991 is an apocalyptic number.

671099991 is a deficient number, since it is larger than the sum of its proper divisors (258732969).

671099991 is a wasteful number, since it uses less digits than its factorization.

671099991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34846.

The product of its (nonzero) digits is 275562, while the sum is 51.

The square root of 671099991 is about 25905.5976769501. The cubic root of 671099991 is about 875.5126208729.

The spelling of 671099991 in words is "six hundred seventy-one million, ninety-nine thousand, nine hundred ninety-one".