2511991 has 8 divisors (see below), whose sum is σ = 2642400. Its totient is φ = 2383392.

The previous prime is 2511983. The next prime is 2511997. The reversal of 2511991 is 1991152.

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 2511991 - 2³ = 2511983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2511997) 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, 3061 + ... + 3793.

It is an arithmetic number, because the mean of its divisors is an integer number (330300).

2^2511991 is an apocalyptic number.

2511991 is a deficient number, since it is larger than the sum of its proper divisors (130409).

2511991 is a wasteful number, since it uses less digits than its factorization.

2511991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 905.

The product of its digits is 810, while the sum is 28.

The square root of 2511991 is about 1584.9261812463. The cubic root of 2511991 is about 135.9375253710.

The spelling of 2511991 in words is "two million, five hundred eleven thousand, nine hundred ninety-one".