138426978 has 16 divisors (see below), whose sum is σ = 276971616. Its totient is φ = 46122720.

The previous prime is 138426973. The next prime is 138426979. The reversal of 138426978 is 879624831.

It is not an unprimeable number, because it can be changed into a prime (138426973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20598 + ... + 26478.

It is an arithmetic number, because the mean of its divisors is an integer number (17310726).

Almost surely, 2^138426978 is an apocalyptic number.

138426978 is an abundant number, since it is smaller than the sum of its proper divisors (138544638).

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

138426978 is a wasteful number, since it uses less digits than its factorization.

138426978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9809.

The product of its digits is 580608, while the sum is 48.

The square root of 138426978 is about 11765.4994794101. The cubic root of 138426978 is about 517.2973408898.

The spelling of 138426978 in words is "one hundred thirty-eight million, four hundred twenty-six thousand, nine hundred seventy-eight".