1181721 has 24 divisors (see below), whose sum is σ = 1768320. Its totient is φ = 700672.

The previous prime is 1181701. The next prime is 1181723. The reversal of 1181721 is 1271811.

It is not a de Polignac number, because 1181721 - 2⁹ = 1181209 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1181723) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25120 + ... + 25166.

It is an arithmetic number, because the mean of its divisors is an integer number (73680).

2^1181721 is an apocalyptic number.

It is an amenable number.

1181721 is a deficient number, since it is larger than the sum of its proper divisors (586599).

1181721 is a wasteful number, since it uses less digits than its factorization.

1181721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 96 counting only the distinct ones).

The product of its digits is 112, while the sum is 21.

The square root of 1181721 is about 1087.0699149549. The cubic root of 1181721 is about 105.7235289667.

The spelling of 1181721 in words is "one million, one hundred eighty-one thousand, seven hundred twenty-one".