2001211020 has 72 divisors (see below), whose sum is σ = 6116750640. Its totient is φ = 529576320.

The previous prime is 2001210989. The next prime is 2001211027. The reversal of 2001211020 is 201121002.

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 = 2001210993 and 2001211011.

It is not an unprimeable number, because it can be changed into a prime (2001211027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18855 + ... + 66014.

It is an arithmetic number, because the mean of its divisors is an integer number (84954870).

Almost surely, 2^2001211020 is an apocalyptic number.

2001211020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001211020 is an abundant number, since it is smaller than the sum of its proper divisors (4115539620).

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

2001211020 is a wasteful number, since it uses less digits than its factorization.

2001211020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85015 (or 85010 counting only the distinct ones).

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

The square root of 2001211020 is about 44734.8971162335. The cubic root of 2001211020 is about 1260.1752968504.

Adding to 2001211020 its reverse (201121002), we get a palindrome (2202332022).

The spelling of 2001211020 in words is "two billion, one million, two hundred eleven thousand, twenty".