7639440138 has 24 divisors (see below), whose sum is σ = 18056858976. Its totient is φ = 2314981800.

The previous prime is 7639440131. The next prime is 7639440191. The reversal of 7639440138 is 8310449367.

7639440138 is a `hidden beast` number, since 7 + 639 + 4 + 4 + 0 + 1 + 3 + 8 = 666.

It is a super-2 number, since 2×7639440138² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 7639440093 and 7639440102.

It is not an unprimeable number, because it can be changed into a prime (7639440131) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19291318 + ... + 19291713.

It is an arithmetic number, because the mean of its divisors is an integer number (752369124).

Almost surely, 2^7639440138 is an apocalyptic number.

7639440138 is an abundant number, since it is smaller than the sum of its proper divisors (10417418838).

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

7639440138 is a wasteful number, since it uses less digits than its factorization.

7639440138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38583050 (or 38583047 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The square root of 7639440138 is about 87403.8908630503. The cubic root of 7639440138 is about 1969.4902902841.

The spelling of 7639440138 in words is "seven billion, six hundred thirty-nine million, four hundred forty thousand, one hundred thirty-eight".