1020201021 has 32 divisors (see below), whose sum is σ = 1762592000. Its totient is φ = 582966720.

The previous prime is 1020201019. The next prime is 1020201031. The reversal of 1020201021 is 1201020201.

It is not a de Polignac number, because 1020201021 - 2¹ = 1020201019 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1020200994 and 1020201012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020201031) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 45820 + ... + 64341.

It is an arithmetic number, because the mean of its divisors is an integer number (55081000).

Almost surely, 2^1020201021 is an apocalyptic number.

It is an amenable number.

1020201021 is a deficient number, since it is larger than the sum of its proper divisors (742390979).

1020201021 is an equidigital number, since it uses as much as digits as its factorization.

1020201021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110191 (or 110171 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1020201021 is about 31940.5857961309. The cubic root of 1020201021 is about 1006.6888334202.

Adding to 1020201021 its reverse (1201020201), we get a palindrome (2221221222).

It can be divided in two parts, 102020 and 1021, that added together give a square (103041 = 321²).

The spelling of 1020201021 in words is "one billion, twenty million, two hundred one thousand, twenty-one".