138775002640 has 20 divisors (see below), whose sum is σ = 322651881324. Its totient is φ = 55510001024.

The previous prime is 138775002617. The next prime is 138775002643. The reversal of 138775002640 is 46200577831.

It can be written as a sum of positive squares in 2 ways, for example, as 91552235776 + 47222766864 = 302576^2 + 217308^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (138775002643) 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, 867343687 + ... + 867343846.

Almost surely, 2^138775002640 is an apocalyptic number.

138775002640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138775002640 is an abundant number, since it is smaller than the sum of its proper divisors (183876878684).

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

138775002640 is a wasteful number, since it uses less digits than its factorization.

138775002640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1734687546 (or 1734687540 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 43.

The spelling of 138775002640 in words is "one hundred thirty-eight billion, seven hundred seventy-five million, two thousand, six hundred forty".