20668830 has 128 divisors (see below), whose sum is σ = 62512128. Its totient is φ = 4257792.

The previous prime is 20668819. The next prime is 20668831. The reversal of 20668830 is 3886602.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20668791 and 20668800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20668831) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 182854 + ... + 182966.

It is an arithmetic number, because the mean of its divisors is an integer number (488376).

Almost surely, 2^20668830 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20668830, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31256064).

20668830 is an abundant number, since it is smaller than the sum of its proper divisors (41843298).

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

20668830 is a wasteful number, since it uses less digits than its factorization.

20668830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 20668830 is about 4546.2984943798. The cubic root of 20668830 is about 274.4344520515.

The spelling of 20668830 in words is "twenty million, six hundred sixty-eight thousand, eight hundred thirty".