138203978 has 16 divisors (see below), whose sum is σ = 231412896. Its totient is φ = 61358640.

The previous prime is 138203977. The next prime is 138203993. The reversal of 138203978 is 879302831.

It is not an unprimeable number, because it can be changed into a prime (138203977) 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 in 7 ways as a sum of consecutive naturals, for example, 72101 + ... + 73992.

It is an arithmetic number, because the mean of its divisors is an integer number (14463306).

Almost surely, 2^138203978 is an apocalyptic number.

138203978 is a deficient number, since it is larger than the sum of its proper divisors (93208918).

138203978 is a wasteful number, since it uses less digits than its factorization.

138203978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146149.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 138203978 is about 11756.0187988962. The cubic root of 138203978 is about 517.0194102210.

The spelling of 138203978 in words is "one hundred thirty-eight million, two hundred three thousand, nine hundred seventy-eight".