42245687138 has 54 divisors (see below), whose sum is σ = 67953043137. Its totient is φ = 19696070240.

The previous prime is 42245687137. The next prime is 42245687167. The reversal of 42245687138 is 83178654224.

It can be written as a sum of positive squares in 2 ways, for example, as 37762982929 + 4482704209 = 194327^2 + 66953^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=145337.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42245687137) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 474670598 + ... + 474670686.

Almost surely, 2^42245687138 is an apocalyptic number.

42245687138 is a deficient number, since it is larger than the sum of its proper divisors (25707355999).

42245687138 is an frugal number, since it uses more digits than its factorization.

42245687138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368 (or 185 counting only the distinct ones).

The product of its digits is 2580480, while the sum is 50.

Multiplying 42245687138 by its sum of digits (50), we get a square (2112284356900 = 1453370²).

The spelling of 42245687138 in words is "forty-two billion, two hundred forty-five million, six hundred eighty-seven thousand, one hundred thirty-eight".