278378497 has 4 divisors (see below), whose sum is σ = 280381360. Its totient is φ = 276375636.

The previous prime is 278378483. The next prime is 278378521. The reversal of 278378497 is 794873872.

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 a de Polignac number, because none of the positive numbers 2^k-278378497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (278378437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1001223 + ... + 1001500.

It is an arithmetic number, because the mean of its divisors is an integer number (70095340).

Almost surely, 2^278378497 is an apocalyptic number.

It is an amenable number.

278378497 is a deficient number, since it is larger than the sum of its proper divisors (2002863).

278378497 is a wasteful number, since it uses less digits than its factorization.

278378497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2002862.

The product of its digits is 4741632, while the sum is 55.

The square root of 278378497 is about 16684.6785105377. The cubic root of 278378497 is about 652.9479487945.

The spelling of 278378497 in words is "two hundred seventy-eight million, three hundred seventy-eight thousand, four hundred ninety-seven".