340642630021 has 2 divisors, whose sum is σ = 340642630022. Its totient is φ = 340642630020.

The previous prime is 340642630019. The next prime is 340642630057. The reversal of 340642630021 is 120036246043.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 332826301921 + 7816328100 = 576911^2 + 88410^2 .

It is a cyclic number.

It is not a de Polignac number, because 340642630021 - 2¹ = 340642630019 is a prime.

Together with 340642630019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (340642630091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170321315010 + 170321315011.

It is an arithmetic number, because the mean of its divisors is an integer number (170321315011).

Almost surely, 2^340642630021 is an apocalyptic number.

It is an amenable number.

340642630021 is a deficient number, since it is larger than the sum of its proper divisors (1).

340642630021 is an equidigital number, since it uses as much as digits as its factorization.

340642630021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 31.

Adding to 340642630021 its reverse (120036246043), we get a palindrome (460678876064).

The spelling of 340642630021 in words is "three hundred forty billion, six hundred forty-two million, six hundred thirty thousand, twenty-one".