231978535 has 4 divisors (see below), whose sum is σ = 278374248. Its totient is φ = 185582824.

The previous prime is 231978521. The next prime is 231978553. The reversal of 231978535 is 535879132.

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

It is a cyclic number.

It is not a de Polignac number, because 231978535 - 2²⁷ = 97760807 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 231978491 and 231978500.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23197849 + ... + 23197858.

It is an arithmetic number, because the mean of its divisors is an integer number (69593562).

Almost surely, 2^231978535 is an apocalyptic number.

231978535 is a deficient number, since it is larger than the sum of its proper divisors (46395713).

231978535 is an equidigital number, since it uses as much as digits as its factorization.

231978535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46395712.

The product of its digits is 226800, while the sum is 43.

The square root of 231978535 is about 15230.8415722835. The cubic root of 231978535 is about 614.4444141847. Note that the first 4 decimals are identical.

The spelling of 231978535 in words is "two hundred thirty-one million, nine hundred seventy-eight thousand, five hundred thirty-five".