20866232184 has 128 divisors (see below), whose sum is σ = 61604167680. Its totient is φ = 5763542400.

The previous prime is 20866232173. The next prime is 20866232209. The reversal of 20866232184 is 48123266802.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8242999 + ... + 8245529.

It is an arithmetic number, because the mean of its divisors is an integer number (481282560).

Almost surely, 2^20866232184 is an apocalyptic number.

20866232184 is a gapful number since it is divisible by the number (24) 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 20866232184, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30802083840).

20866232184 is an abundant number, since it is smaller than the sum of its proper divisors (40737935496).

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

20866232184 is a wasteful number, since it uses less digits than its factorization.

20866232184 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4161 (or 4157 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 42.

Adding to 20866232184 its reverse (48123266802), we get a palindrome (68989498986).

The spelling of 20866232184 in words is "twenty billion, eight hundred sixty-six million, two hundred thirty-two thousand, one hundred eighty-four".