2813729781 has 4 divisors (see below), whose sum is σ = 3751639712. Its totient is φ = 1875819852.

The previous prime is 2813729759. The next prime is 2813729791. The reversal of 2813729781 is 1879273182.

It is a happy number.

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.

It is not a de Polignac number, because 2813729781 - 2²⁶ = 2746620917 is a prime.

It is a super-2 number, since 2×2813729781² = 15834150560972615922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2813729781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2813729791) 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, 468954961 + ... + 468954966.

It is an arithmetic number, because the mean of its divisors is an integer number (937909928).

Almost surely, 2^2813729781 is an apocalyptic number.

It is an amenable number.

2813729781 is a deficient number, since it is larger than the sum of its proper divisors (937909931).

2813729781 is an equidigital number, since it uses as much as digits as its factorization.

2813729781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 937909930.

The product of its digits is 338688, while the sum is 48.

The square root of 2813729781 is about 53044.6018082896. The cubic root of 2813729781 is about 1411.7597499163.

The spelling of 2813729781 in words is "two billion, eight hundred thirteen million, seven hundred twenty-nine thousand, seven hundred eighty-one".