345768781 has 2 divisors, whose sum is σ = 345768782. Its totient is φ = 345768780.

The previous prime is 345768757. The next prime is 345768791. The reversal of 345768781 is 187867543.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211440681 + 134328100 = 14541^2 + 11590^2 .

It is a cyclic number.

It is not a de Polignac number, because 345768781 - 2¹³ = 345760589 is a prime.

It is a super-2 number, since 2×345768781² = 239112099828451922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (345768791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172884390 + 172884391.

It is an arithmetic number, because the mean of its divisors is an integer number (172884391).

Almost surely, 2^345768781 is an apocalyptic number.

It is an amenable number.

345768781 is a deficient number, since it is larger than the sum of its proper divisors (1).

345768781 is an equidigital number, since it uses as much as digits as its factorization.

345768781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1128960, while the sum is 49.

The square root of 345768781 is about 18594.8589938187. The cubic root of 345768781 is about 701.8784790043.

The spelling of 345768781 in words is "three hundred forty-five million, seven hundred sixty-eight thousand, seven hundred eighty-one".