4991531 has 4 divisors (see below), whose sum is σ = 4996152. Its totient is φ = 4986912.

The previous prime is 4991507. The next prime is 4991543. The reversal of 4991531 is 1351994.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4991531 is a prime.

It is a super-2 number, since 2×4991531² = 49830763447922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4991551) 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, 275 + ... + 3171.

It is an arithmetic number, because the mean of its divisors is an integer number (1249038).

Almost surely, 2^4991531 is an apocalyptic number.

4991531 is a deficient number, since it is larger than the sum of its proper divisors (4621).

4991531 is a wasteful number, since it uses less digits than its factorization.

4991531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4620.

The product of its digits is 4860, while the sum is 32.

The square root of 4991531 is about 2234.1734489515. The cubic root of 4991531 is about 170.9009948649.

The spelling of 4991531 in words is "four million, nine hundred ninety-one thousand, five hundred thirty-one".