2136581 has 4 divisors (see below), whose sum is σ = 2139552. Its totient is φ = 2133612.

The previous prime is 2136559. The next prime is 2136583. The reversal of 2136581 is 1856312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, 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-2136581 is a prime.

It is a super-2 number, since 2×2136581² = 9129956739122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 2136581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2136583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 350 + ... + 2096.

It is an arithmetic number, because the mean of its divisors is an integer number (534888).

2^2136581 is an apocalyptic number.

It is an amenable number.

2136581 is a deficient number, since it is larger than the sum of its proper divisors (2971).

2136581 is a wasteful number, since it uses less digits than its factorization.

2136581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2970.

The product of its digits is 1440, while the sum is 26.

The square root of 2136581 is about 1461.7048265638. The cubic root of 2136581 is about 128.7972095701.

The spelling of 2136581 in words is "two million, one hundred thirty-six thousand, five hundred eighty-one".