2781231 has 4 divisors (see below), whose sum is σ = 3708312. Its totient is φ = 1854152.

The previous prime is 2781221. The next prime is 2781271. The reversal of 2781231 is 1321872.

2781231 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2781231 - 2⁵ = 2781199 is a prime.

It is a super-2 number, since 2×2781231² = 15470491750722, which contains 22 as substring.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2781211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 463536 + ... + 463541.

It is an arithmetic number, because the mean of its divisors is an integer number (927078).

2^2781231 is an apocalyptic number.

2781231 is a deficient number, since it is larger than the sum of its proper divisors (927081).

2781231 is an equidigital number, since it uses as much as digits as its factorization.

2781231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 927080.

The product of its digits is 672, while the sum is 24.

The square root of 2781231 is about 1667.7023115652. The cubic root of 2781231 is about 140.6303379702.

It can be divided in two parts, 2781 and 231, that multiplied together give a triangular number (642411 = T₁₁₃₃).

The spelling of 2781231 in words is "two million, seven hundred eighty-one thousand, two hundred thirty-one".