1281855641 has 16 divisors (see below), whose sum is σ = 1482053760. Its totient is φ = 1095732480.

The previous prime is 1281855629. The next prime is 1281855683. The reversal of 1281855641 is 1465581821.

It is a cyclic number.

It is not a de Polignac number, because 1281855641 - 2¹⁰ = 1281854617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1281855541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 244055 + ... + 249251.

It is an arithmetic number, because the mean of its divisors is an integer number (92628360).

Almost surely, 2^1281855641 is an apocalyptic number.

1281855641 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1281855641 is a deficient number, since it is larger than the sum of its proper divisors (200198119).

1281855641 is a wasteful number, since it uses less digits than its factorization.

1281855641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6544.

The product of its digits is 76800, while the sum is 41.

The square root of 1281855641 is about 35803.0116191362. The cubic root of 1281855641 is about 1086.2914791908.

The spelling of 1281855641 in words is "one billion, two hundred eighty-one million, eight hundred fifty-five thousand, six hundred forty-one".