278778720025 has 27 divisors (see below), whose sum is σ = 374368378269. Its totient is φ = 205842018720.

The previous prime is 278778720023. The next prime is 278778720049. The reversal of 278778720025 is 520027877872.

The square root of 278778720025 is 527995.

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

It can be written as a sum of positive squares in 4 ways, for example, as 71855627481 + 206923092544 = 268059^2 + 454888^2 .

It is not a de Polignac number, because 278778720025 - 2¹ = 278778720023 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (278778720023) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 34315614 + ... + 34323736.

Almost surely, 2^278778720025 is an apocalyptic number.

278778720025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

278778720025 is the 527995-th square number.

278778720025 is the 263998-th centered octagonal number.

It is an amenable number.

278778720025 is a deficient number, since it is larger than the sum of its proper divisors (95589658244).

278778720025 is an frugal number, since it uses more digits than its factorization.

278778720025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16282 (or 8141 counting only the distinct ones).

The product of its (nonzero) digits is 6146560, while the sum is 55.

The spelling of 278778720025 in words is "two hundred seventy-eight billion, seven hundred seventy-eight million, seven hundred twenty thousand, twenty-five".