278328961 has 4 divisors (see below), whose sum is σ = 278540032. Its totient is φ = 278117892.

The previous prime is 278328959. The next prime is 278328991. The reversal of 278328961 is 169823872.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 278328961 - 2¹ = 278328959 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (278328931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103545 + ... + 106198.

It is an arithmetic number, because the mean of its divisors is an integer number (69635008).

Almost surely, 2^278328961 is an apocalyptic number.

It is an amenable number.

278328961 is a deficient number, since it is larger than the sum of its proper divisors (211071).

278328961 is a wasteful number, since it uses less digits than its factorization.

278328961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211070.

The product of its digits is 290304, while the sum is 46.

The square root of 278328961 is about 16683.1939687819. The cubic root of 278328961 is about 652.9092169377.

The spelling of 278328961 in words is "two hundred seventy-eight million, three hundred twenty-eight thousand, nine hundred sixty-one".