21020012312220 has 144 divisors (see below), whose sum is σ = 64646482424160. Its totient is φ = 5528532766464.

The previous prime is 21020012312213. The next prime is 21020012312231. The reversal of 21020012312220 is 2221321002012.

21020012312220 is a `hidden beast` number, since 2 + 10 + 200 + 1 + 231 + 2 + 220 = 666.

It is a super-2 number, since 2×21020012312220² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21020012312193 and 21020012312202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 69872967 + ... + 70173153.

Almost surely, 2^{21020012312220} is an apocalyptic number.

21020012312220 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 21020012312220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32323241212080).

21020012312220 is an abundant number, since it is smaller than the sum of its proper divisors (43626470111940).

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

21020012312220 is an equidigital number, since it uses as much as digits as its factorization.

21020012312220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300421 (or 300270 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21020012312220 its reverse (2221321002012), we get a palindrome (23241333314232).

The spelling of 21020012312220 in words is "twenty-one trillion, twenty billion, twelve million, three hundred twelve thousand, two hundred twenty".