1281201855 has 32 divisors (see below), whose sum is σ = 2198016000. Its totient is φ = 634962432.

The previous prime is 1281201853. The next prime is 1281201869. The reversal of 1281201855 is 5581021821.

It is not a de Polignac number, because 1281201855 - 2¹ = 1281201853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281201853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11655 + ... + 51944.

It is an arithmetic number, because the mean of its divisors is an integer number (68688000).

Almost surely, 2^1281201855 is an apocalyptic number.

1281201855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1281201855 is a deficient number, since it is larger than the sum of its proper divisors (916814145).

1281201855 is a wasteful number, since it uses less digits than its factorization.

1281201855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63703.

The product of its (nonzero) digits is 6400, while the sum is 33.

The square root of 1281201855 is about 35793.8801333412. The cubic root of 1281201855 is about 1086.1067670401.

The spelling of 1281201855 in words is "one billion, two hundred eighty-one million, two hundred one thousand, eight hundred fifty-five".