139218905 has 16 divisors (see below), whose sum is σ = 192824064. Its totient is φ = 94516800.

The previous prime is 139218889. The next prime is 139218913. The reversal of 139218905 is 509812931.

139218905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 139218905 - 2⁴ = 139218889 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16157 + ... + 23226.

It is an arithmetic number, because the mean of its divisors is an integer number (12051504).

Almost surely, 2^139218905 is an apocalyptic number.

It is an amenable number.

139218905 is a deficient number, since it is larger than the sum of its proper divisors (53605159).

139218905 is a wasteful number, since it uses less digits than its factorization.

139218905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39496.

The product of its (nonzero) digits is 19440, while the sum is 38.

The square root of 139218905 is about 11799.1061102102. The cubic root of 139218905 is about 518.2819345948.

The spelling of 139218905 in words is "one hundred thirty-nine million, two hundred eighteen thousand, nine hundred five".