278421841 has 4 divisors (see below), whose sum is σ = 279427252. Its totient is φ = 277416432.

The previous prime is 278421827. The next prime is 278421853. The reversal of 278421841 is 148124872.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 85100625 + 193321216 = 9225^2 + 13904^2 .

It is a cyclic number.

It is not a de Polignac number, because 278421841 - 2⁷ = 278421713 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 278421841.

It is not an unprimeable number, because it can be changed into a prime (278421821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 502290 + ... + 502843.

It is an arithmetic number, because the mean of its divisors is an integer number (69856813).

Almost surely, 2^278421841 is an apocalyptic number.

It is an amenable number.

278421841 is a deficient number, since it is larger than the sum of its proper divisors (1005411).

278421841 is a wasteful number, since it uses less digits than its factorization.

278421841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1005410.

The product of its digits is 28672, while the sum is 37.

The square root of 278421841 is about 16685.9773762282. The cubic root of 278421841 is about 652.9818354003.

The spelling of 278421841 in words is "two hundred seventy-eight million, four hundred twenty-one thousand, eight hundred forty-one".