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BaseRepresentation
bin10110100101000100…
…01110011100100101
31011021210220121021021
423102202032130211
5144311230401041
65322511051141
7606253223422
oct132242163445
934253817237
1012122122021
115160692769
122423810ab1
1311b2552589
154ae344cd1
hex2d288e725

12122122021 has 4 divisors (see below), whose sum is σ = 12123900844. Its totient is φ = 12120343200.

The previous prime is 12122121989. The next prime is 12122122049. The reversal of 12122122021 is 12022122121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7693219521 + 4428902500 = 87711^2 + 66550^2 .

It is a cyclic number.

It is not a de Polignac number, because 12122122021 - 25 = 12122121989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12122121986 and 12122122004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12122122081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 879150 + ... + 892831.

It is an arithmetic number, because the mean of its divisors is an integer number (3030975211).

Almost surely, 212122122021 is an apocalyptic number.

It is an amenable number.

12122122021 is a deficient number, since it is larger than the sum of its proper divisors (1778823).

12122122021 is an equidigital number, since it uses as much as digits as its factorization.

12122122021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1778822.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 12122122021 its reverse (12022122121), we get a palindrome (24144244142).

The spelling of 12122122021 in words is "twelve billion, one hundred twenty-two million, one hundred twenty-two thousand, twenty-one".

Divisors: 1 6841 1771981 12122122021