2144455781 has 4 divisors (see below), whose sum is σ = 2309413932. Its totient is φ = 1979497632.

The previous prime is 2144455771. The next prime is 2144455787. The reversal of 2144455781 is 1875544412.

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 1234468225 + 909987556 = 35135^2 + 30166^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2144455781 is a prime.

It is a super-2 number, since 2×2144455781² = 9197381193328639922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2144455787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82479056 + ... + 82479081.

It is an arithmetic number, because the mean of its divisors is an integer number (577353483).

Almost surely, 2^2144455781 is an apocalyptic number.

It is an amenable number.

2144455781 is a deficient number, since it is larger than the sum of its proper divisors (164958151).

2144455781 is a wasteful number, since it uses less digits than its factorization.

2144455781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164958150.

The product of its digits is 179200, while the sum is 41.

The square root of 2144455781 is about 46308.2690348063. The cubic root of 2144455781 is about 1289.5525120966.

The spelling of 2144455781 in words is "two billion, one hundred forty-four million, four hundred fifty-five thousand, seven hundred eighty-one".