1109121681 has 4 divisors (see below), whose sum is σ = 1478828912. Its totient is φ = 739414452.

The previous prime is 1109121677. The next prime is 1109121683. The reversal of 1109121681 is 1861219011.

It is a happy number.

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.

It is not a de Polignac number, because 1109121681 - 2² = 1109121677 is a prime.

It is a super-2 number, since 2×1109121681² = 2460301806528531522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1109121683) 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, 184853611 + ... + 184853616.

It is an arithmetic number, because the mean of its divisors is an integer number (369707228).

Almost surely, 2^1109121681 is an apocalyptic number.

It is an amenable number.

1109121681 is a deficient number, since it is larger than the sum of its proper divisors (369707231).

1109121681 is an equidigital number, since it uses as much as digits as its factorization.

1109121681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369707230.

The product of its (nonzero) digits is 864, while the sum is 30.

The square root of 1109121681 is about 33303.4785120113. The cubic root of 1109121681 is about 1035.1256371558.

The spelling of 1109121681 in words is "one billion, one hundred nine million, one hundred twenty-one thousand, six hundred eighty-one".