20819660 has 24 divisors (see below), whose sum is σ = 44278080. Its totient is φ = 8221824.

The previous prime is 20819657. The next prime is 20819683. The reversal of 20819660 is 6691802.

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, 5009 + ... + 8168.

It is an arithmetic number, because the mean of its divisors is an integer number (1844920).

Almost surely, 2^20819660 is an apocalyptic number.

20819660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20819660 is an abundant number, since it is smaller than the sum of its proper divisors (23458420).

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

20819660 is a wasteful number, since it uses less digits than its factorization.

20819660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13265 (or 13263 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 20819660 is about 4562.8565614097. The cubic root of 20819660 is about 275.1003930975.

The spelling of 20819660 in words is "twenty million, eight hundred nineteen thousand, six hundred sixty".