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21099977 is a prime number
BaseRepresentation
bin101000001111…
…1010111001001
31110200222201122
41100133113021
520400144402
62032125025
7344226653
oct120372711
943628648
1021099977
1110a017a8
127096775
1344a9cc2
142b336d3
151cbbca2
hex141f5c9

21099977 has 2 divisors, whose sum is σ = 21099978. Its totient is φ = 21099976.

The previous prime is 21099973. The next prime is 21100003. The reversal of 21099977 is 77999012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16516096 + 4583881 = 4064^2 + 2141^2 .

It is a cyclic number.

It is not a de Polignac number, because 21099977 - 22 = 21099973 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21099973) 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 as a sum of consecutive naturals, namely, 10549988 + 10549989.

It is an arithmetic number, because the mean of its divisors is an integer number (10549989).

Almost surely, 221099977 is an apocalyptic number.

It is an amenable number.

21099977 is a deficient number, since it is larger than the sum of its proper divisors (1).

21099977 is an equidigital number, since it uses as much as digits as its factorization.

21099977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 71442, while the sum is 44.

The square root of 21099977 is about 4593.4711275897. The cubic root of 21099977 is about 276.3295484213.

The spelling of 21099977 in words is "twenty-one million, ninety-nine thousand, nine hundred seventy-seven".