231989138 has 4 divisors (see below), whose sum is σ = 347983710. Its totient is φ = 115994568.

The previous prime is 231989117. The next prime is 231989143. The reversal of 231989138 is 831989132.

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., 226592809 + 5396329 = 15053^2 + 2323^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57997283 + ... + 57997286.

Almost surely, 2^231989138 is an apocalyptic number.

231989138 is a deficient number, since it is larger than the sum of its proper divisors (115994572).

231989138 is a wasteful number, since it uses less digits than its factorization.

231989138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115994571.

The product of its digits is 93312, while the sum is 44.

The square root of 231989138 is about 15231.1896449358. The cubic root of 231989138 is about 614.4537754745.

The spelling of 231989138 in words is "two hundred thirty-one million, nine hundred eighty-nine thousand, one hundred thirty-eight".