2181344257 has 4 divisors (see below), whose sum is σ = 2181541936. Its totient is φ = 2181146580.

The previous prime is 2181344251. The next prime is 2181344281. The reversal of 2181344257 is 7524431812.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2181344257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2181344251) 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, 81243 + ... + 104704.

It is an arithmetic number, because the mean of its divisors is an integer number (545385484).

Almost surely, 2^2181344257 is an apocalyptic number.

It is an amenable number.

2181344257 is a deficient number, since it is larger than the sum of its proper divisors (197679).

2181344257 is a wasteful number, since it uses less digits than its factorization.

2181344257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197678.

The product of its digits is 53760, while the sum is 37.

The square root of 2181344257 is about 46704.8633120792. The cubic root of 2181344257 is about 1296.9047182754.

The spelling of 2181344257 in words is "two billion, one hundred eighty-one million, three hundred forty-four thousand, two hundred fifty-seven".