1280537856 has 144 divisors (see below), whose sum is σ = 4078352320. Its totient is φ = 393984000.

The previous prime is 1280537821. The next prime is 1280537899. The reversal of 1280537856 is 6587350821.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 82731 + ... + 96981.

Almost surely, 2^1280537856 is an apocalyptic number.

1280537856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1280537856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2039176160).

1280537856 is an abundant number, since it is smaller than the sum of its proper divisors (2797814464).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1280537856 is a wasteful number, since it uses less digits than its factorization.

1280537856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14289 (or 14269 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The square root of 1280537856 is about 35784.6036166394. The cubic root of 1280537856 is about 1085.9191051126.

The spelling of 1280537856 in words is "one billion, two hundred eighty million, five hundred thirty-seven thousand, eight hundred fifty-six".