1279981 has 12 divisors (see below), whose sum is σ = 1404832. Its totient is φ = 1165248.

The previous prime is 1279969. The next prime is 1279997. The reversal of 1279981 is 1899721.

It is not a de Polignac number, because 1279981 - 2⁷ = 1279853 is a prime.

It is a super-2 number, since 2×1279981² = 3276702720722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1279981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1279921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12376 + ... + 12478.

2^1279981 is an apocalyptic number.

It is an amenable number.

1279981 is a deficient number, since it is larger than the sum of its proper divisors (124851).

1279981 is a wasteful number, since it uses less digits than its factorization.

1279981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180 (or 163 counting only the distinct ones).

The product of its digits is 9072, while the sum is 37.

The square root of 1279981 is about 1131.3624529743. The cubic root of 1279981 is about 108.5761674327.

It can be divided in two parts, 12799 and 81, that added together give a triangular number (12880 = T₁₆₀).

The spelling of 1279981 in words is "one million, two hundred seventy-nine thousand, nine hundred eighty-one".