1281957728 has 24 divisors (see below), whose sum is σ = 2524760280. Its totient is φ = 640748800.

The previous prime is 1281957713. The next prime is 1281957737. The reversal of 1281957728 is 8277591821.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115628 + ... + 126228.

It is an arithmetic number, because the mean of its divisors is an integer number (105198345).

Almost surely, 2^1281957728 is an apocalyptic number.

It is an amenable number.

1281957728 is a deficient number, since it is larger than the sum of its proper divisors (1242802552).

1281957728 is a wasteful number, since it uses less digits than its factorization.

1281957728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14390 (or 14382 counting only the distinct ones).

The product of its digits is 564480, while the sum is 50.

The square root of 1281957728 is about 35804.4372669087. The cubic root of 1281957728 is about 1086.3203158478.

The spelling of 1281957728 in words is "one billion, two hundred eighty-one million, nine hundred fifty-seven thousand, seven hundred twenty-eight".