7827238721 has 4 divisors (see below), whose sum is σ = 8167553472. Its totient is φ = 7486923972.

The previous prime is 7827238691. The next prime is 7827238759. The reversal of 7827238721 is 1278327287.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1278327287 = 197 ⋅6488971.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7827238721 is a prime.

It is a super-2 number, since 2×7827238721² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7827238781) 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, 170157341 + ... + 170157386.

It is an arithmetic number, because the mean of its divisors is an integer number (2041888368).

Almost surely, 2^7827238721 is an apocalyptic number.

It is an amenable number.

7827238721 is a deficient number, since it is larger than the sum of its proper divisors (340314751).

7827238721 is a wasteful number, since it uses less digits than its factorization.

7827238721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340314750.

The product of its digits is 526848, while the sum is 47.

The square root of 7827238721 is about 88471.6831590764. The cubic root of 7827238721 is about 1985.4983316980.

The spelling of 7827238721 in words is "seven billion, eight hundred twenty-seven million, two hundred thirty-eight thousand, seven hundred twenty-one".