138779254 has 4 divisors (see below), whose sum is σ = 208168884. Its totient is φ = 69389626.

The previous prime is 138779243. The next prime is 138779257. The reversal of 138779254 is 452977831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 452977831 = 14347 ⋅31573.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138779257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34694812 + ... + 34694815.

It is an arithmetic number, because the mean of its divisors is an integer number (52042221).

Almost surely, 2^138779254 is an apocalyptic number.

138779254 is a deficient number, since it is larger than the sum of its proper divisors (69389630).

138779254 is an equidigital number, since it uses as much as digits as its factorization.

138779254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69389629.

The product of its digits is 423360, while the sum is 46.

The square root of 138779254 is about 11780.4606870869. The cubic root of 138779254 is about 517.7357840193.

The spelling of 138779254 in words is "one hundred thirty-eight million, seven hundred seventy-nine thousand, two hundred fifty-four".