1181329921 has 16 divisors (see below), whose sum is σ = 1253789440. Its totient is φ = 1109946240.

The previous prime is 1181329889. The next prime is 1181329943. The reversal of 1181329921 is 1299231811.

It is a cyclic number.

It is not a de Polignac number, because 1181329921 - 2⁵ = 1181329889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1181329321) 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, 1611271 + ... + 1612003.

It is an arithmetic number, because the mean of its divisors is an integer number (78361840).

Almost surely, 2^1181329921 is an apocalyptic number.

It is an amenable number.

1181329921 is a deficient number, since it is larger than the sum of its proper divisors (72459519).

1181329921 is a wasteful number, since it uses less digits than its factorization.

1181329921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1336.

The product of its digits is 7776, while the sum is 37.

The square root of 1181329921 is about 34370.4803719704. The cubic root of 1181329921 is about 1057.1186495752.

The spelling of 1181329921 in words is "one billion, one hundred eighty-one million, three hundred twenty-nine thousand, nine hundred twenty-one".