16666423220 has 24 divisors (see below), whose sum is σ = 35039252808. Its totient is φ = 6658995200.

The previous prime is 16666423219. The next prime is 16666423271. The reversal of 16666423220 is 2232466661.

It can be written as a sum of positive squares in 4 ways, for example, as 1932833296 + 14733589924 = 43964^2 + 121382^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 455321 + ... + 490560.

It is an arithmetic number, because the mean of its divisors is an integer number (1459968867).

Almost surely, 2^16666423220 is an apocalyptic number.

16666423220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16666423220 is an abundant number, since it is smaller than the sum of its proper divisors (18372829588).

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

16666423220 is a wasteful number, since it uses less digits than its factorization.

16666423220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 946771 (or 946769 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 38.

Adding to 16666423220 its reverse (2232466661), we get a palindrome (18898889881).

The spelling of 16666423220 in words is "sixteen billion, six hundred sixty-six million, four hundred twenty-three thousand, two hundred twenty".