138540646787 has 4 divisors (see below), whose sum is σ = 146690096616. Its totient is φ = 130391196960.

The previous prime is 138540646757. The next prime is 138540646817. The reversal of 138540646787 is 787646045831.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (138540646757) and next prime (138540646817).

It is a cyclic number.

It is not a de Polignac number, because 138540646787 - 2²⁴ = 138523869571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138540646747) 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, 4074724889 + ... + 4074724922.

It is an arithmetic number, because the mean of its divisors is an integer number (36672524154).

Almost surely, 2^138540646787 is an apocalyptic number.

138540646787 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

138540646787 is a deficient number, since it is larger than the sum of its proper divisors (8149449829).

138540646787 is an equidigital number, since it uses as much as digits as its factorization.

138540646787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8149449828.

The product of its (nonzero) digits is 27095040, while the sum is 59.

The spelling of 138540646787 in words is "one hundred thirty-eight billion, five hundred forty million, six hundred forty-six thousand, seven hundred eighty-seven".