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20102021 = 162112401
BaseRepresentation
bin100110010101…
…1101110000101
31101211021210022
41030223232011
520121231041
61554504525
7332602322
oct114535605
941737708
1020102021
111038aa45
126895145
13421a9b4
142953b49
151b7124b
hex132bb85

20102021 has 4 divisors (see below), whose sum is σ = 20116044. Its totient is φ = 20088000.

The previous prime is 20102009. The next prime is 20102029. The reversal of 20102021 is 12020102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12020102 = 26010051.

It can be written as a sum of positive squares in 2 ways, for example, as 11628100 + 8473921 = 3410^2 + 2911^2 .

It is a cyclic number.

It is not a de Polignac number, because 20102021 - 218 = 19839877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20102029) 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 3 ways as a sum of consecutive naturals, for example, 4580 + ... + 7821.

It is an arithmetic number, because the mean of its divisors is an integer number (5029011).

Almost surely, 220102021 is an apocalyptic number.

It is an amenable number.

20102021 is a deficient number, since it is larger than the sum of its proper divisors (14023).

20102021 is a wasteful number, since it uses less digits than its factorization.

20102021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14022.

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

The square root of 20102021 is about 4483.5277405186. The cubic root of 20102021 is about 271.9025250857.

Adding to 20102021 its reverse (12020102), we get a palindrome (32122123).

The spelling of 20102021 in words is "twenty million, one hundred two thousand, twenty-one".

Divisors: 1 1621 12401 20102021