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19199981 is a prime number
BaseRepresentation
bin100100100111…
…1011111101101
31100010110102102
41021033133231
514403344411
61523304445
7322124423
oct111173755
940113372
1019199981
11a924259
12651b125
133c93248
14279b113
151a43d3b
hex124f7ed

19199981 has 2 divisors, whose sum is σ = 19199982. Its totient is φ = 19199980.

The previous prime is 19199977. The next prime is 19200007. The reversal of 19199981 is 18999191.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18139081 + 1060900 = 4259^2 + 1030^2 .

It is an emirp because it is prime and its reverse (18999191) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 18666161 and 16166681.

It is a cyclic number.

It is not a de Polignac number, because 19199981 - 22 = 19199977 is a prime.

It is a super-2 number, since 2×191999812 = 737278540800722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19199951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9599990 + 9599991.

It is an arithmetic number, because the mean of its divisors is an integer number (9599991).

Almost surely, 219199981 is an apocalyptic number.

It is an amenable number.

19199981 is a deficient number, since it is larger than the sum of its proper divisors (1).

19199981 is an equidigital number, since it uses as much as digits as its factorization.

19199981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52488, while the sum is 47.

The square root of 19199981 is about 4381.7782919723. The cubic root of 19199981 is about 267.7730917049.

The spelling of 19199981 in words is "nineteen million, one hundred ninety-nine thousand, nine hundred eighty-one".