20010201666 has 128 divisors (see below), whose sum is σ = 51066892800. Its totient is φ = 5084190720.

The previous prime is 20010201649. The next prime is 20010201677. The reversal of 20010201666 is 66610201002.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9008436 + ... + 9010656.

It is an arithmetic number, because the mean of its divisors is an integer number (398960100).

Almost surely, 2^20010201666 is an apocalyptic number.

20010201666 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 20010201666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25533446400).

20010201666 is an abundant number, since it is smaller than the sum of its proper divisors (31056691134).

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

20010201666 is a wasteful number, since it uses less digits than its factorization.

20010201666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2844.

The product of its (nonzero) digits is 864, while the sum is 24.

Adding to 20010201666 its reverse (66610201002), we get a palindrome (86620402668).

The spelling of 20010201666 in words is "twenty billion, ten million, two hundred one thousand, six hundred sixty-six".