1281185257 has 16 divisors (see below), whose sum is σ = 1495350720. Its totient is φ = 1085313600.

The previous prime is 1281185251. The next prime is 1281185293. The reversal of 1281185257 is 7525811821.

It is a cyclic number.

It is not a de Polignac number, because 1281185257 - 2¹¹ = 1281183209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1281185251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37498 + ... + 62995.

It is an arithmetic number, because the mean of its divisors is an integer number (93459420).

Almost surely, 2^1281185257 is an apocalyptic number.

It is an amenable number.

1281185257 is a deficient number, since it is larger than the sum of its proper divisors (214165463).

1281185257 is a wasteful number, since it uses less digits than its factorization.

1281185257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100584.

The product of its digits is 44800, while the sum is 40.

The square root of 1281185257 is about 35793.6482773131. The cubic root of 1281185257 is about 1086.1020768404.

The spelling of 1281185257 in words is "one billion, two hundred eighty-one million, one hundred eighty-five thousand, two hundred fifty-seven".