278389225 has 27 divisors (see below), whose sum is σ = 357741271. Its totient is φ = 214902800.

The previous prime is 278389211. The next prime is 278389247. The reversal of 278389225 is 522983872.

The square root of 278389225 is 16685.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 100220121 + 178169104 = 10011^2 + 13348^2 .

It is not a de Polignac number, because 278389225 - 2¹¹ = 278387177 is a prime.

It is a super-2 number, since 2×278389225² = 155001121192201250, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 3920940 + ... + 3921010.

Almost surely, 2^278389225 is an apocalyptic number.

278389225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

278389225 is the 16685-th square number.

278389225 is the 8343-rd centered octagonal number.

It is an amenable number.

278389225 is a deficient number, since it is larger than the sum of its proper divisors (79352046).

278389225 is an frugal number, since it uses more digits than its factorization.

278389225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246 (or 123 counting only the distinct ones).

The product of its digits is 483840, while the sum is 46.

The cubic root of 278389225 is about 652.9563363384.

The spelling of 278389225 in words is "two hundred seventy-eight million, three hundred eighty-nine thousand, two hundred twenty-five".