1281920 has 32 divisors (see below), whose sum is σ = 3066120. Its totient is φ = 512512.

The previous prime is 1281899. The next prime is 1281937. The reversal of 1281920 is 291821.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 362 + ... + 1641.

2^1281920 is an apocalyptic number.

1281920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1281920 is an abundant number, since it is smaller than the sum of its proper divisors (1784200).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1281920 is an equidigital number, since it uses as much as digits as its factorization.

1281920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2022 (or 2010 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1281920 is about 1132.2190600763. The cubic root of 1281920 is about 108.6309658945.

Subtracting from 1281920 its reverse (291821), we obtain a palindrome (990099).

It can be divided in two parts, 128 and 1920, that added together give a 11-th power (2048 = 2¹¹).

The spelling of 1281920 in words is "one million, two hundred eighty-one thousand, nine hundred twenty".