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216021389 is a prime number
BaseRepresentation
bin11001110000000…
…11100110001101
3120001111000122012
430320003212031
5420300141024
633234031005
75232102653
oct1470034615
9501430565
10216021389
11100a36081
1260418465
13359a680c
1420992dd3
1513e7150e
hexce0398d

216021389 has 2 divisors, whose sum is σ = 216021390. Its totient is φ = 216021388.

The previous prime is 216021383. The next prime is 216021391. The reversal of 216021389 is 983120612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 212284900 + 3736489 = 14570^2 + 1933^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-216021389 is a prime.

Together with 216021391, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p11915528 and since 216021389 and 11915528 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216021383) 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, 108010694 + 108010695.

It is an arithmetic number, because the mean of its divisors is an integer number (108010695).

Almost surely, 2216021389 is an apocalyptic number.

It is an amenable number.

216021389 is a deficient number, since it is larger than the sum of its proper divisors (1).

216021389 is an equidigital number, since it uses as much as digits as its factorization.

216021389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 216021389 is about 14697.6661072430. Note that the first 3 decimals coincide. The cubic root of 216021389 is about 600.0198039760.

The spelling of 216021389 in words is "two hundred sixteen million, twenty-one thousand, three hundred eighty-nine".