20668100 has 54 divisors (see below), whose sum is σ = 46599882. Its totient is φ = 7952000.

The previous prime is 20668091. The next prime is 20668111. The reversal of 20668100 is 186602.

It can be written as a sum of positive squares in 3 ways, for example, as 20164 + 20647936 = 142^2 + 4544^2 .

It is a super-2 number, since 2×20668100² = 854340715220000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 291065 + ... + 291135.

Almost surely, 2^20668100 is an apocalyptic number.

20668100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20668100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23299941).

20668100 is an abundant number, since it is smaller than the sum of its proper divisors (25931782).

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

20668100 is a wasteful number, since it uses less digits than its factorization.

20668100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 20668100 is about 4546.2182085773. The cubic root of 20668100 is about 274.4312211073.

The spelling of 20668100 in words is "twenty million, six hundred sixty-eight thousand, one hundred".