231388978 has 8 divisors (see below), whose sum is σ = 348403968. Its totient is φ = 115254324.

The previous prime is 231388967. The next prime is 231388981. The reversal of 231388978 is 879883132.

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

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, 219426 + ... + 220477.

It is an arithmetic number, because the mean of its divisors is an integer number (43550496).

Almost surely, 2^231388978 is an apocalyptic number.

231388978 is a deficient number, since it is larger than the sum of its proper divisors (117014990).

231388978 is a wasteful number, since it uses less digits than its factorization.

231388978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440168.

The product of its digits is 580608, while the sum is 49.

The square root of 231388978 is about 15211.4752078817. The cubic root of 231388978 is about 613.9234502988.

The spelling of 231388978 in words is "two hundred thirty-one million, three hundred eighty-eight thousand, nine hundred seventy-eight".