2668640381 has 4 divisors (see below), whose sum is σ = 2911244064. Its totient is φ = 2426036700.

The previous prime is 2668640369. The next prime is 2668640393. The reversal of 2668640381 is 1830468662.

2668640381 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (2668640369) and next prime (2668640393).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2668640381 is a prime.

It is a super-2 number, since 2×2668640381² = 14243282966207650322, 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 (2668640311) 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, 121301825 + ... + 121301846.

It is an arithmetic number, because the mean of its divisors is an integer number (727811016).

Almost surely, 2^2668640381 is an apocalyptic number.

It is an amenable number.

2668640381 is a deficient number, since it is larger than the sum of its proper divisors (242603683).

2668640381 is a wasteful number, since it uses less digits than its factorization.

2668640381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242603682.

The product of its (nonzero) digits is 331776, while the sum is 44.

The square root of 2668640381 is about 51658.8848214903. The cubic root of 2668640381 is about 1387.0645886004.

The spelling of 2668640381 in words is "two billion, six hundred sixty-eight million, six hundred forty thousand, three hundred eighty-one".