1166221720 has 32 divisors (see below), whose sum is σ = 2659950720. Its totient is φ = 460097280.

The previous prime is 1166221717. The next prime is 1166221733. The reversal of 1166221720 is 271226611.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 196776 + ... + 202615.

It is an arithmetic number, because the mean of its divisors is an integer number (83123460).

Almost surely, 2^1166221720 is an apocalyptic number.

1166221720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1166221720 is an abundant number, since it is smaller than the sum of its proper divisors (1493729000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1166221720 is a wasteful number, since it uses less digits than its factorization.

1166221720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399475 (or 399471 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 1166221720 is about 34149.9885797931. The cubic root of 1166221720 is about 1052.5927519661.

The spelling of 1166221720 in words is "one billion, one hundred sixty-six million, two hundred twenty-one thousand, seven hundred twenty".