1280381557 has 16 divisors (see below), whose sum is σ = 1658796160. Its totient is φ = 959729472.

The previous prime is 1280381551. The next prime is 1280381563. The reversal of 1280381557 is 7551830821.

It is an interprime number because it is at equal distance from previous prime (1280381551) and next prime (1280381563).

It is not a de Polignac number, because 1280381557 - 2⁷ = 1280381429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1280381551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 368538 + ... + 371995.

It is an arithmetic number, because the mean of its divisors is an integer number (103674760).

Almost surely, 2^1280381557 is an apocalyptic number.

It is an amenable number.

1280381557 is a deficient number, since it is larger than the sum of its proper divisors (378414603).

1280381557 is a wasteful number, since it uses less digits than its factorization.

1280381557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 740572.

The product of its (nonzero) digits is 67200, while the sum is 40.

The square root of 1280381557 is about 35782.4196638517. The cubic root of 1280381557 is about 1085.8749218617.

The spelling of 1280381557 in words is "one billion, two hundred eighty million, three hundred eighty-one thousand, five hundred fifty-seven".