210001020 has 24 divisors (see below), whose sum is σ = 588003024. Its totient is φ = 56000256.

The previous prime is 210001009. The next prime is 210001021. The reversal of 210001020 is 20100012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210001021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1749949 + ... + 1750068.

It is an arithmetic number, because the mean of its divisors is an integer number (24500126).

Almost surely, 2^210001020 is an apocalyptic number.

210001020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

210001020 is an abundant number, since it is smaller than the sum of its proper divisors (378002004).

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

210001020 is a wasteful number, since it uses less digits than its factorization.

210001020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3500029 (or 3500027 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 6.

The square root of 210001020 is about 14491.4119394902. The cubic root of 210001020 is about 594.3931576240.

Adding to 210001020 its reverse (20100012), we get a palindrome (230101032).

The spelling of 210001020 in words is "two hundred ten million, one thousand, twenty".