278562261 has 4 divisors (see below), whose sum is σ = 371416352. Its totient is φ = 185708172.

The previous prime is 278562239. The next prime is 278562301. The reversal of 278562261 is 162265872.

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 not a de Polignac number, because 278562261 - 2⁷ = 278562133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278562761) 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, 46427041 + ... + 46427046.

It is an arithmetic number, because the mean of its divisors is an integer number (92854088).

Almost surely, 2^278562261 is an apocalyptic number.

It is an amenable number.

278562261 is a deficient number, since it is larger than the sum of its proper divisors (92854091).

278562261 is an equidigital number, since it uses as much as digits as its factorization.

278562261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92854090.

The product of its digits is 80640, while the sum is 39.

The square root of 278562261 is about 16690.1845705792. The cubic root of 278562261 is about 653.0915924733.

The spelling of 278562261 in words is "two hundred seventy-eight million, five hundred sixty-two thousand, two hundred sixty-one".