1129981 has 4 divisors (see below), whose sum is σ = 1166464. Its totient is φ = 1093500.

The previous prime is 1129963. The next prime is 1129991. The reversal of 1129981 is 1899211.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1899211 = 211 ⋅9001.

It is a 7-Lehmer number, since φ(1129981) divides (1129981-1)⁷.

It is a cyclic number.

It is not a de Polignac number, because 1129981 - 2⁷ = 1129853 is a prime.

It is a super-2 number, since 2×1129981² = 2553714120722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 36451 = 1129981 / (1 + 1 + 2 + 9 + 9 + 8 + 1).

It is an Ulam number.

It is a Duffinian number.

1129981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1129951) 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, 18195 + ... + 18256.

It is an arithmetic number, because the mean of its divisors is an integer number (291616).

2^1129981 is an apocalyptic number.

It is an amenable number.

1129981 is a deficient number, since it is larger than the sum of its proper divisors (36483).

1129981 is an equidigital number, since it uses as much as digits as its factorization.

1129981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36482.

The product of its digits is 1296, while the sum is 31.

The square root of 1129981 is about 1063.0056443876. The cubic root of 1129981 is about 104.1574599507.

It can be divided in two parts, 11 and 29981, that added together give a palindrome (29992).

The spelling of 1129981 in words is "one million, one hundred twenty-nine thousand, nine hundred eighty-one".