278980643 has 4 divisors (see below), whose sum is σ = 279016440. Its totient is φ = 278944848.

The previous prime is 278980631. The next prime is 278980657. The reversal of 278980643 is 346089872.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 278980643 - 2⁴ = 278980627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (278980043) 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, 698 + ... + 23631.

It is an arithmetic number, because the mean of its divisors is an integer number (69754110).

Almost surely, 2^278980643 is an apocalyptic number.

278980643 is a deficient number, since it is larger than the sum of its proper divisors (35797).

278980643 is a wasteful number, since it uses less digits than its factorization.

278980643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35796.

The product of its (nonzero) digits is 580608, while the sum is 47.

The square root of 278980643 is about 16702.7136418008. The cubic root of 278980643 is about 653.4183956360.

The spelling of 278980643 in words is "two hundred seventy-eight million, nine hundred eighty thousand, six hundred forty-three".