2640123221 has 8 divisors (see below), whose sum is σ = 2656982040. Its totient is φ = 2623315968.

The previous prime is 2640123181. The next prime is 2640123223. The reversal of 2640123221 is 1223210462.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1897560721 + 742562500 = 43561^2 + 27250^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2640123221 - 2²² = 2635928917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2640123223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 92555 + ... + 117671.

It is an arithmetic number, because the mean of its divisors is an integer number (332122755).

Almost surely, 2^2640123221 is an apocalyptic number.

It is an amenable number.

2640123221 is a deficient number, since it is larger than the sum of its proper divisors (16858819).

2640123221 is a wasteful number, since it uses less digits than its factorization.

2640123221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25783.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 2640123221 is about 51382.1293933990. The cubic root of 2640123221 is about 1382.1061484268.

Adding to 2640123221 its reverse (1223210462), we get a palindrome (3863333683).

The spelling of 2640123221 in words is "two billion, six hundred forty million, one hundred twenty-three thousand, two hundred twenty-one".