340018781 has 4 divisors (see below), whose sum is σ = 348311964. Its totient is φ = 331725600.

The previous prime is 340018747. The next prime is 340018799. The reversal of 340018781 is 187810043.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 187810043 = 10313 ⋅18211.

It can be written as a sum of positive squares in 2 ways, for example, as 81613156 + 258405625 = 9034^2 + 16075^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-340018781 is a prime.

It is a super-2 number, since 2×340018781² = 231225542865451922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (340018741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4146530 + ... + 4146611.

It is an arithmetic number, because the mean of its divisors is an integer number (87077991).

Almost surely, 2^340018781 is an apocalyptic number.

It is an amenable number.

340018781 is a deficient number, since it is larger than the sum of its proper divisors (8293183).

340018781 is an equidigital number, since it uses as much as digits as its factorization.

340018781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8293182.

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 340018781 is about 18439.5981789192. The cubic root of 340018781 is about 697.9660556887.

The spelling of 340018781 in words is "three hundred forty million, eighteen thousand, seven hundred eighty-one".