138601778 has 32 divisors (see below), whose sum is σ = 249260544. Its totient is φ = 56555712.

The previous prime is 138601777. The next prime is 138601781. The reversal of 138601778 is 877106831.

It is a super-2 number, since 2×138601778² = 38420905729522568, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138601777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21500 + ... + 27192.

It is an arithmetic number, because the mean of its divisors is an integer number (7789392).

Almost surely, 2^138601778 is an apocalyptic number.

138601778 is a deficient number, since it is larger than the sum of its proper divisors (110658766).

138601778 is a wasteful number, since it uses less digits than its factorization.

138601778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5786.

The product of its (nonzero) digits is 56448, while the sum is 41.

The square root of 138601778 is about 11772.9256346925. The cubic root of 138601778 is about 517.5149900362.

The spelling of 138601778 in words is "one hundred thirty-eight million, six hundred one thousand, seven hundred seventy-eight".