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2001111221 is a prime number
BaseRepresentation
bin111011101000110…
…1000100010110101
312011110102222112102
41313101220202311
513044241024341
6530322431445
7100406110334
oct16721504265
95143388472
102001111221
1193763652a
1247a202585
1325b7760a5
1414daa7d1b
15baa31c9b
hex774688b5

2001111221 has 2 divisors, whose sum is σ = 2001111222. Its totient is φ = 2001111220.

The previous prime is 2001111209. The next prime is 2001111223. The reversal of 2001111221 is 1221111002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1351371121 + 649740100 = 36761^2 + 25490^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-2001111221 is a prime.

It is a super-2 number, since 2×20011112212 = 8008892237624221682, which contains 22 as substring.

Together with 2001111223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2001111223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000555610 + 1000555611.

It is an arithmetic number, because the mean of its divisors is an integer number (1000555611).

Almost surely, 22001111221 is an apocalyptic number.

It is an amenable number.

2001111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001111221 is an equidigital number, since it uses as much as digits as its factorization.

2001111221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 2001111221 is about 44733.7816532428. The cubic root of 2001111221 is about 1260.1543484807.

Adding to 2001111221 its reverse (1221111002), we get a palindrome (3222222223).

The spelling of 2001111221 in words is "two billion, one million, one hundred eleven thousand, two hundred twenty-one".