231217978 has 8 divisors (see below), whose sum is σ = 349558272. Its totient is φ = 114698556.

The previous prime is 231217967. The next prime is 231217993. The reversal of 231217978 is 879712132.

It is a happy number.

231217978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 231217978.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 454900 + ... + 455407.

It is an arithmetic number, because the mean of its divisors is an integer number (43694784).

Almost surely, 2^231217978 is an apocalyptic number.

231217978 is a deficient number, since it is larger than the sum of its proper divisors (118340294).

231217978 is a wasteful number, since it uses less digits than its factorization.

231217978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910436.

The product of its digits is 42336, while the sum is 40.

The square root of 231217978 is about 15205.8534124198. The cubic root of 231217978 is about 613.7721800837.

The spelling of 231217978 in words is "two hundred thirty-one million, two hundred seventeen thousand, nine hundred seventy-eight".