138777537 has 4 divisors (see below), whose sum is σ = 185036720. Its totient is φ = 92518356.

The previous prime is 138777517. The next prime is 138777563. The reversal of 138777537 is 735777831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 138777537 - 2¹⁸ = 138515393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138777517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23129587 + ... + 23129592.

It is an arithmetic number, because the mean of its divisors is an integer number (46259180).

Almost surely, 2^138777537 is an apocalyptic number.

It is an amenable number.

138777537 is a deficient number, since it is larger than the sum of its proper divisors (46259183).

138777537 is an equidigital number, since it uses as much as digits as its factorization.

138777537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46259182.

The product of its digits is 864360, while the sum is 48.

The square root of 138777537 is about 11780.3878119525. The cubic root of 138777537 is about 517.7336488394.

The spelling of 138777537 in words is "one hundred thirty-eight million, seven hundred seventy-seven thousand, five hundred thirty-seven".