2021101020 has 72 divisors (see below), whose sum is σ = 6190250976. Its totient is φ = 533722752.

The previous prime is 2021101009. The next prime is 2021101039. The reversal of 2021101020 is 201011202.

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 = 2021100993 and 2021101011.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35967 + ... + 73046.

It is an arithmetic number, because the mean of its divisors is an integer number (85975708).

Almost surely, 2^2021101020 is an apocalyptic number.

2021101020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2021101020 is an abundant number, since it is smaller than the sum of its proper divisors (4169149956).

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

2021101020 is a wasteful number, since it uses less digits than its factorization.

2021101020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109131 (or 109126 counting only the distinct ones).

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

The square root of 2021101020 is about 44956.6571266147. The cubic root of 2021101020 is about 1264.3364942600.

Adding to 2021101020 its reverse (201011202), we get a palindrome (2222112222).

It can be divided in two parts, 2021 and 101020, that added together give a square (103041 = 321²).

The spelling of 2021101020 in words is "two billion, twenty-one million, one hundred one thousand, twenty".