6411991 has 4 divisors (see below), whose sum is σ = 6478192. Its totient is φ = 6345792.

The previous prime is 6411973. The next prime is 6411997. The reversal of 6411991 is 1991146.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1991146 = 2 ⋅995573.

It is a cyclic number.

It is not a de Polignac number, because 6411991 - 2¹¹ = 6409943 is a prime.

It is a super-2 number, since 2×6411991² = 82227257168162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6411997) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32955 + ... + 33148.

It is an arithmetic number, because the mean of its divisors is an integer number (1619548).

Almost surely, 2^6411991 is an apocalyptic number.

6411991 is a deficient number, since it is larger than the sum of its proper divisors (66201).

6411991 is an equidigital number, since it uses as much as digits as its factorization.

6411991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66200.

The product of its digits is 1944, while the sum is 31.

The square root of 6411991 is about 2532.1909485661. The cubic root of 6411991 is about 185.7794336948.

The spelling of 6411991 in words is "six million, four hundred eleven thousand, nine hundred ninety-one".