1161966721 has 8 divisors (see below), whose sum is σ = 1175911488. Its totient is φ = 1148070000.

The previous prime is 1161966697. The next prime is 1161966731. The reversal of 1161966721 is 1276691611.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1161966721 - 2⁹ = 1161966209 is a prime.

It is a super-2 number, since 2×1161966721² = 2700333321422983682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1161966731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37876 + ... + 61306.

It is an arithmetic number, because the mean of its divisors is an integer number (146988936).

Almost surely, 2^1161966721 is an apocalyptic number.

It is an amenable number.

1161966721 is a deficient number, since it is larger than the sum of its proper divisors (13944767).

1161966721 is a wasteful number, since it uses less digits than its factorization.

1161966721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24023.

The product of its digits is 27216, while the sum is 40.

The square root of 1161966721 is about 34087.6329627036. The cubic root of 1161966721 is about 1051.3110519565.

The spelling of 1161966721 in words is "one billion, one hundred sixty-one million, nine hundred sixty-six thousand, seven hundred twenty-one".