1280381 has 4 divisors (see below), whose sum is σ = 1283772. Its totient is φ = 1276992.

The previous prime is 1280371. The next prime is 1280399. The reversal of 1280381 is 1830821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 188356 + 1092025 = 434^2 + 1045^2 .

It is a cyclic number.

It is not a de Polignac number, because 1280381 - 2⁶ = 1280317 is a prime.

It is a super-2 number, since 2×1280381² = 3278751010322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1280371) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1046 + ... + 1911.

It is an arithmetic number, because the mean of its divisors is an integer number (320943).

2^1280381 is an apocalyptic number.

It is an amenable number.

1280381 is a deficient number, since it is larger than the sum of its proper divisors (3391).

1280381 is an equidigital number, since it uses as much as digits as its factorization.

1280381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3390.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 1280381 is about 1131.5392171728. The cubic root of 1280381 is about 108.5874764400.

It can be divided in two parts, 1280 and 381, that added together give a palindrome (1661).

The spelling of 1280381 in words is "one million, two hundred eighty thousand, three hundred eighty-one".