138578436 has 18 divisors (see below), whose sum is σ = 350295582. Its totient is φ = 46192800.

The previous prime is 138578423. The next prime is 138578449. The reversal of 138578436 is 634875831.

138578436 is a `hidden beast` number, since 1 + 38 + 578 + 43 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (138578423) and next prime (138578449).

It can be written as a sum of positive squares in only one way, i.e., 98128836 + 40449600 = 9906^2 + 6360^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a junction number, because it is equal to n+sod(n) for n = 138578391 and 138578400.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1924665 + ... + 1924736.

Almost surely, 2^138578436 is an apocalyptic number.

It is an amenable number.

138578436 is an abundant number, since it is smaller than the sum of its proper divisors (211717146).

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

138578436 is a wasteful number, since it uses less digits than its factorization.

138578436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3849411 (or 3849406 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 138578436 is about 11771.9342505809. The cubic root of 138578436 is about 517.4859367459.

The spelling of 138578436 in words is "one hundred thirty-eight million, five hundred seventy-eight thousand, four hundred thirty-six".