1020000021220 has 24 divisors (see below), whose sum is σ = 2142533978424. Its totient is φ = 407898306816.

The previous prime is 1020000021169. The next prime is 1020000021247. The reversal of 1020000021220 is 221200000201.

It can be written as a sum of positive squares in 4 ways, for example, as 324107044416 + 695892976804 = 569304^2 + 834202^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 1020000021197 and 1020000021206.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6274089 + ... + 6434608.

It is an arithmetic number, because the mean of its divisors is an integer number (89272249101).

Almost surely, 2^{1020000021220} is an apocalyptic number.

1020000021220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1020000021220 is an abundant number, since it is smaller than the sum of its proper divisors (1122533957204).

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

1020000021220 is a wasteful number, since it uses less digits than its factorization.

1020000021220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12712719 (or 12712717 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 1020000021220 its reverse (221200000201), we get a palindrome (1241200021421).

The spelling of 1020000021220 in words is "one trillion, twenty billion, twenty-one thousand, two hundred twenty".