1231281 has 16 divisors (see below), whose sum is σ = 1849920. Its totient is φ = 819396.

The previous prime is 1231277. The next prime is 1231283. The reversal of 1231281 is 1821321.

It is not a de Polignac number, because 1231281 - 2² = 1231277 is a prime.

It is a super-2 number, since 2×1231281² = 3032105801922, which contains 22 as substring.

1231281 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1231283) 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, 1906 + ... + 2468.

It is an arithmetic number, because the mean of its divisors is an integer number (115620).

2^1231281 is an apocalyptic number.

It is an amenable number.

1231281 is a deficient number, since it is larger than the sum of its proper divisors (618639).

1231281 is an frugal number, since it uses more digits than its factorization.

1231281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 584 (or 566 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

The square root of 1231281 is about 1109.6310197539. The cubic root of 1231281 is about 107.1813096267.

The spelling of 1231281 in words is "one million, two hundred thirty-one thousand, two hundred eighty-one".