840438108401 has 2 divisors, whose sum is σ = 840438108402. Its totient is φ = 840438108400.

The previous prime is 840438108373. The next prime is 840438108439. The reversal of 840438108401 is 104801834048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 641722757776 + 198715350625 = 801076^2 + 445775^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-840438108401 is a prime.

It is not a weakly prime, because it can be changed into another prime (840438108101) 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, 420219054200 + 420219054201.

It is an arithmetic number, because the mean of its divisors is an integer number (420219054201).

Almost surely, 2^840438108401 is an apocalyptic number.

It is an amenable number.

840438108401 is a deficient number, since it is larger than the sum of its proper divisors (1).

840438108401 is an equidigital number, since it uses as much as digits as its factorization.

840438108401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 98304, while the sum is 41.

The spelling of 840438108401 in words is "eight hundred forty billion, four hundred thirty-eight million, one hundred eight thousand, four hundred one".