1281813 has 16 divisors (see below), whose sum is σ = 1921920. Its totient is φ = 753984.

The previous prime is 1281809. The next prime is 1281821. The reversal of 1281813 is 3181821.

It is not a de Polignac number, because 1281813 - 2² = 1281809 is a prime.

1281813 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 183 + ... + 1611.

It is an arithmetic number, because the mean of its divisors is an integer number (120120).

2^1281813 is an apocalyptic number.

1281813 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1281813 is a deficient number, since it is larger than the sum of its proper divisors (640107).

1281813 is a wasteful number, since it uses less digits than its factorization.

1281813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1468.

The product of its digits is 384, while the sum is 24.

The square root of 1281813 is about 1132.1718067502. The cubic root of 1281813 is about 108.6279433875.

The spelling of 1281813 in words is "one million, two hundred eighty-one thousand, eight hundred thirteen".