7921381844 has 12 divisors (see below), whose sum is σ = 13864252500. Its totient is φ = 3960166848.

The previous prime is 7921381843. The next prime is 7921381873. The reversal of 7921381844 is 4481831297.

It can be written as a sum of positive squares in 2 ways, for example, as 2302080400 + 5619301444 = 47980^2 + 74962^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7921381843) 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, 95969 + ... + 158280.

It is an arithmetic number, because the mean of its divisors is an integer number (1155354375).

Almost surely, 2^7921381844 is an apocalyptic number.

It is an amenable number.

7921381844 is a deficient number, since it is larger than the sum of its proper divisors (5942870656).

7921381844 is a wasteful number, since it uses less digits than its factorization.

7921381844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262042 (or 262040 counting only the distinct ones).

The product of its digits is 387072, while the sum is 47.

The square root of 7921381844 is about 89002.1451651588. The cubic root of 7921381844 is about 1993.4269078963.

The spelling of 7921381844 in words is "seven billion, nine hundred twenty-one million, three hundred eighty-one thousand, eight hundred forty-four".