278643238 has 4 divisors (see below), whose sum is σ = 417964860. Its totient is φ = 139321618.

The previous prime is 278643217. The next prime is 278643241. The reversal of 278643238 is 832346872.

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

It is a junction number, because it is equal to n+sod(n) for n = 278643194 and 278643203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69660808 + ... + 69660811.

It is an arithmetic number, because the mean of its divisors is an integer number (104491215).

Almost surely, 2^278643238 is an apocalyptic number.

278643238 is a deficient number, since it is larger than the sum of its proper divisors (139321622).

278643238 is a wasteful number, since it uses less digits than its factorization.

278643238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139321621.

The product of its digits is 387072, while the sum is 43.

The square root of 278643238 is about 16692.6102811993. The cubic root of 278643238 is about 653.1548700975.

The spelling of 278643238 in words is "two hundred seventy-eight million, six hundred forty-three thousand, two hundred thirty-eight".