7809522138 has 48 divisors (see below), whose sum is σ = 18771760800. Its totient is φ = 2326407840.

The previous prime is 7809522137. The next prime is 7809522173. The reversal of 7809522138 is 8312259087.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 7809522093 and 7809522102.

It is not an unprimeable number, because it can be changed into a prime (7809522137) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 322573 + ... + 345936.

It is an arithmetic number, because the mean of its divisors is an integer number (391078350).

Almost surely, 2^7809522138 is an apocalyptic number.

7809522138 is an abundant number, since it is smaller than the sum of its proper divisors (10962238662).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7809522138 is a wasteful number, since it uses less digits than its factorization.

7809522138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 668587 (or 668584 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The square root of 7809522138 is about 88371.5007114850. The cubic root of 7809522138 is about 1983.9991729870. Note that the first 3 decimals are identical.

The spelling of 7809522138 in words is "seven billion, eight hundred nine million, five hundred twenty-two thousand, one hundred thirty-eight".