5111991 has 24 divisors (see below), whose sum is σ = 7767760. Its totient is φ = 3359232.

The previous prime is 5111963. The next prime is 5111999. The reversal of 5111991 is 1991115.

It is not a de Polignac number, because 5111991 - 2⁶ = 5111927 is a prime.

It is a super-2 number, since 2×5111991² = 52264903968162, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5111999) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26391 + ... + 26583.

Almost surely, 2^5111991 is an apocalyptic number.

5111991 is a deficient number, since it is larger than the sum of its proper divisors (2655769).

5111991 is a wasteful number, since it uses less digits than its factorization.

5111991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317 (or 305 counting only the distinct ones).

The product of its digits is 405, while the sum is 27.

The square root of 5111991 is about 2260.9712514758. The cubic root of 5111991 is about 172.2648592011.

It can be divided in two parts, 5 and 111991, that multiplied together give a palindrome (559955).

The spelling of 5111991 in words is "five million, one hundred eleven thousand, nine hundred ninety-one".