30905138 has 16 divisors (see below), whose sum is σ = 51940224. Its totient is φ = 13667760.

The previous prime is 30905129. The next prime is 30905143. The reversal of 30905138 is 83150903.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 30905138.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18170 + ... + 19797.

It is an arithmetic number, because the mean of its divisors is an integer number (3246264).

Almost surely, 2^30905138 is an apocalyptic number.

30905138 is a deficient number, since it is larger than the sum of its proper divisors (21035086).

30905138 is a wasteful number, since it uses less digits than its factorization.

30905138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38017.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 30905138 is about 5559.2389766946. The cubic root of 30905138 is about 313.8173102571.

It can be divided in two parts, 3090 and 5138, that added together give a palindrome (8228).

The spelling of 30905138 in words is "thirty million, nine hundred five thousand, one hundred thirty-eight".