20161666433220 has 72 divisors (see below), whose sum is σ = 61129218257856. Its totient is φ = 4962871734912.

The previous prime is 20161666433213. The next prime is 20161666433221. The reversal of 20161666433220 is 2233466616102.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (20161666433221) 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, 994154872 + ... + 994175151.

It is an arithmetic number, because the mean of its divisors is an integer number (849016920248).

Almost surely, 2^{20161666433220} is an apocalyptic number.

20161666433220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20161666433220 is an abundant number, since it is smaller than the sum of its proper divisors (40967551824636).

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

20161666433220 is a wasteful number, since it uses less digits than its factorization.

20161666433220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1988330061 (or 1988330046 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 42.

The spelling of 20161666433220 in words is "twenty trillion, one hundred sixty-one billion, six hundred sixty-six million, four hundred thirty-three thousand, two hundred twenty".