831505138 has 4 divisors (see below), whose sum is σ = 1247257710. Its totient is φ = 415752568.

The previous prime is 831505123. The next prime is 831505141.

831505138 is nontrivially palindromic in base 10.

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

It can be written as a sum of positive squares in only one way, i.e., 819276129 + 12229009 = 28623^2 + 3497^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 207876283 + ... + 207876286.

Almost surely, 2^831505138 is an apocalyptic number.

831505138 is a deficient number, since it is larger than the sum of its proper divisors (415752572).

831505138 is a wasteful number, since it uses less digits than its factorization.

831505138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415752571.

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 831505138 is about 28835.8308012792. The cubic root of 831505138 is about 940.3473659605.

It can be divided in two parts, 83150 and 5138, that added together give a palindrome (88288).

The spelling of 831505138 in words is "eight hundred thirty-one million, five hundred five thousand, one hundred thirty-eight".