343781993 has 2 divisors, whose sum is σ = 343781994. Its totient is φ = 343781992.

The previous prime is 343781987. The next prime is 343782011. The reversal of 343781993 is 399187343.

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., 342694144 + 1087849 = 18512^2 + 1043^2 .

It is an emirp because it is prime and its reverse (399187343) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-343781993 is a prime.

It is a super-2 number, since 2×343781993² = 236372117422104098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (343781983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171890996 + 171890997.

It is an arithmetic number, because the mean of its divisors is an integer number (171890997).

Almost surely, 2^343781993 is an apocalyptic number.

It is an amenable number.

343781993 is a deficient number, since it is larger than the sum of its proper divisors (1).

343781993 is an equidigital number, since it uses as much as digits as its factorization.

343781993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 47.

The square root of 343781993 is about 18541.3589847131. The cubic root of 343781993 is about 700.5315642671.

The spelling of 343781993 in words is "three hundred forty-three million, seven hundred eighty-one thousand, nine hundred ninety-three".