21020021202180 has 384 divisors, whose sum is σ = 81159299665920. Its totient is φ = 3922843944960.

The previous prime is 21020021202151. The next prime is 21020021202181. The reversal of 21020021202180 is 8120212002012.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21020021202181) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2507290 + ... + 6951729.

It is an arithmetic number, because the mean of its divisors is an integer number (211352342880).

Almost surely, 2^{21020021202180} is an apocalyptic number.

21020021202180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020021202180 is an abundant number, since it is smaller than the sum of its proper divisors (60139278463740).

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

21020021202180 is a wasteful number, since it uses less digits than its factorization.

21020021202180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9459099 (or 9459097 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21020021202180 its reverse (8120212002012), we get a palindrome (29140233204192).

The spelling of 21020021202180 in words is "twenty-one trillion, twenty billion, twenty-one million, two hundred two thousand, one hundred eighty".