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20013122021 = 129115502031
BaseRepresentation
bin10010101000111000…
…000000000111100101
31220122202012221021112
4102220320000013211
5311441324401041
613105514354405
71305641505344
oct225070000745
956582187245
1020013122021
11853a981872
123a6642ba05
131b6c320549
14d7bd3db5b
157c1eaddeb
hex4a8e001e5

20013122021 has 4 divisors (see below), whose sum is σ = 20028625344. Its totient is φ = 19997618700.

The previous prime is 20013121979. The next prime is 20013122027. The reversal of 20013122021 is 12022131002.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20013122021 - 210 = 20013120997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20013121987 and 20013122005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20013122027) 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, 7749725 + ... + 7752306.

It is an arithmetic number, because the mean of its divisors is an integer number (5007156336).

Almost surely, 220013122021 is an apocalyptic number.

It is an amenable number.

20013122021 is a deficient number, since it is larger than the sum of its proper divisors (15503323).

20013122021 is a wasteful number, since it uses less digits than its factorization.

20013122021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15503322.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 20013122021 its reverse (12022131002), we get a palindrome (32035253023).

The spelling of 20013122021 in words is "twenty billion, thirteen million, one hundred twenty-two thousand, twenty-one".

Divisors: 1 1291 15502031 20013122021