11142781 has 4 divisors (see below), whose sum is σ = 11999932. Its totient is φ = 10285632.

The previous prime is 11142767. The next prime is 11142821. The reversal of 11142781 is 18724111.

11142781 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 can be written as a sum of positive squares in 2 ways, for example, as 1276900 + 9865881 = 1130^2 + 3141^2 .

It is a cyclic number.

It is not a de Polignac number, because 11142781 - 2⁷ = 11142653 is a prime.

It is a super-2 number, since 2×11142781² = 248323136827922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11142731) 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, 428556 + ... + 428581.

It is an arithmetic number, because the mean of its divisors is an integer number (2999983).

Almost surely, 2^11142781 is an apocalyptic number.

It is an amenable number.

11142781 is a deficient number, since it is larger than the sum of its proper divisors (857151).

11142781 is an equidigital number, since it uses as much as digits as its factorization.

11142781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 857150.

The product of its digits is 448, while the sum is 25.

The square root of 11142781 is about 3338.0804364185. The cubic root of 11142781 is about 223.3561242552.

Adding to 11142781 its reverse (18724111), we get a palindrome (29866892).

The spelling of 11142781 in words is "eleven million, one hundred forty-two thousand, seven hundred eighty-one".