139636478 has 4 divisors (see below), whose sum is σ = 209454720. Its totient is φ = 69818238.

The previous prime is 139636477. The next prime is 139636507. The reversal of 139636478 is 874636931.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139636477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34909118 + ... + 34909121.

It is an arithmetic number, because the mean of its divisors is an integer number (52363680).

Almost surely, 2^139636478 is an apocalyptic number.

139636478 is a deficient number, since it is larger than the sum of its proper divisors (69818242).

139636478 is an equidigital number, since it uses as much as digits as its factorization.

139636478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69818241.

The product of its digits is 653184, while the sum is 47.

The square root of 139636478 is about 11816.7879730492. The cubic root of 139636478 is about 518.7995954324.

The spelling of 139636478 in words is "one hundred thirty-nine million, six hundred thirty-six thousand, four hundred seventy-eight".