1281138849 has 45 divisors (see below), whose sum is σ = 1982047881. Its totient is φ = 824670720.

The previous prime is 1281138841. The next prime is 1281138851. The reversal of 1281138849 is 9488311821.

The square root of 1281138849 is 35793.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 426629025 + 854509824 = 20655^2 + 29232^2 .

It is not a de Polignac number, because 1281138849 - 2³ = 1281138841 is a prime.

Its product of digits (110592) is a multiple of the sum of its prime factors (288).

It is not an unprimeable number, because it can be changed into a prime (1281138841) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 13207569 + ... + 13207665.

Almost surely, 2^1281138849 is an apocalyptic number.

1281138849 is the 35793-rd square number.

1281138849 is the 17897-th centered octagonal number.

It is an amenable number.

1281138849 is a deficient number, since it is larger than the sum of its proper divisors (700909032).

1281138849 is an frugal number, since it uses more digits than its factorization.

1281138849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288 (or 141 counting only the distinct ones).

The product of its digits is 110592, while the sum is 45.

The cubic root of 1281138849 is about 1086.0889628291.

The spelling of 1281138849 in words is "one billion, two hundred eighty-one million, one hundred thirty-eight thousand, eight hundred forty-nine".