138538877 has 4 divisors (see below), whose sum is σ = 141917916. Its totient is φ = 135159840.

The previous prime is 138538853. The next prime is 138538879. The reversal of 138538877 is 778835831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 778835831 = 1973 ⋅394747.

It can be written as a sum of positive squares in 2 ways, for example, as 27994681 + 110544196 = 5291^2 + 10514^2 .

It is a cyclic number.

It is not a de Polignac number, because 138538877 - 2¹⁶ = 138473341 is a prime.

It is a super-2 number, since 2×138538877² = 38386040880842258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138538879) 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, 1689458 + ... + 1689539.

It is an arithmetic number, because the mean of its divisors is an integer number (35479479).

Almost surely, 2^138538877 is an apocalyptic number.

It is an amenable number.

138538877 is a deficient number, since it is larger than the sum of its proper divisors (3379039).

138538877 is an equidigital number, since it uses as much as digits as its factorization.

138538877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3379038.

The product of its digits is 1128960, while the sum is 50.

The square root of 138538877 is about 11770.2539055026. The cubic root of 138538877 is about 517.4366910503.

The spelling of 138538877 in words is "one hundred thirty-eight million, five hundred thirty-eight thousand, eight hundred seventy-seven".