21021010100220 has 96 divisors (see below), whose sum is σ = 64932441053760. Its totient is φ = 5048197539840.

The previous prime is 21021010100177. The next prime is 21021010100297. The reversal of 21021010100220 is 2200101012012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21021010100196 and 21021010100205.

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, 328626715 + ... + 328690674.

It is an arithmetic number, because the mean of its divisors is an integer number (676379594310).

Almost surely, 2^{21021010100220} is an apocalyptic number.

21021010100220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021010100220 is an abundant number, since it is smaller than the sum of its proper divisors (43911430953540).

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

21021010100220 is a wasteful number, since it uses less digits than its factorization.

21021010100220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657317455 (or 657317453 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21021010100220 its reverse (2200101012012), we get a palindrome (23221111112232).

The spelling of 21021010100220 in words is "twenty-one trillion, twenty-one billion, ten million, one hundred thousand, two hundred twenty".