20101020 has 96 divisors (see below), whose sum is σ = 59222016. Its totient is φ = 5088000.

The previous prime is 20101013. The next prime is 20101073. The reversal of 20101020 is 2010102.

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 an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 187807 + ... + 187913.

It is an arithmetic number, because the mean of its divisors is an integer number (616896).

Almost surely, 2^20101020 is an apocalyptic number.

20101020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20101020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29611008).

20101020 is an abundant number, since it is smaller than the sum of its proper divisors (39120996).

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

20101020 is a wasteful number, since it uses less digits than its factorization.

20101020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251 (or 249 counting only the distinct ones).

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

The square root of 20101020 is about 4483.4161082817. The cubic root of 20101020 is about 271.8980117925.

Adding to 20101020 its reverse (2010102), we get a palindrome (22111122).

The spelling of 20101020 in words is "twenty million, one hundred one thousand, twenty".