1280238778 has 48 divisors (see below), whose sum is σ = 2418409224. Its totient is φ = 503798400.

The previous prime is 1280238721. The next prime is 1280238779. The reversal of 1280238778 is 8778320821.

It can be written as a sum of positive squares in 4 ways, for example, as 812079009 + 468159769 = 28497^2 + 21637^2 .

It is a super-2 number, since 2×1280238778² = 3278022657389866568, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1280238779) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 248428 + ... + 253528.

Almost surely, 2^1280238778 is an apocalyptic number.

1280238778 is a deficient number, since it is larger than the sum of its proper divisors (1138170446).

1280238778 is a wasteful number, since it uses less digits than its factorization.

1280238778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5327 (or 5320 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 46.

The square root of 1280238778 is about 35780.4245083817. The cubic root of 1280238778 is about 1085.8345573579.

The spelling of 1280238778 in words is "one billion, two hundred eighty million, two hundred thirty-eight thousand, seven hundred seventy-eight".