220021020 has 72 divisors (see below), whose sum is σ = 680018976. Its totient is φ = 57562752.

The previous prime is 220021019. The next prime is 220021031. The reversal of 220021020 is 20120022.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 220020993 and 220021011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1992 + ... + 21071.

It is an arithmetic number, because the mean of its divisors is an integer number (9444708).

Almost surely, 2^220021020 is an apocalyptic number.

220021020 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 220021020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (340009488).

220021020 is an abundant number, since it is smaller than the sum of its proper divisors (459997956).

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

220021020 is a wasteful number, since it uses less digits than its factorization.

220021020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23131 (or 23126 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 220021020 is about 14833.1055413221. The cubic root of 220021020 is about 603.7002993950.

Adding to 220021020 its reverse (20120022), we get a palindrome (240141042).

It can be divided in two parts, 2200 and 21020, that added together give a triangular number (23220 = T₂₁₅).

The spelling of 220021020 in words is "two hundred twenty million, twenty-one thousand, twenty".