840440929 has 2 divisors, whose sum is σ = 840440930. Its totient is φ = 840440928.

The previous prime is 840440921. The next prime is 840440971. The reversal of 840440929 is 929044048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 839666529 + 774400 = 28977^2 + 880^2 .

It is a cyclic number.

It is not a de Polignac number, because 840440929 - 2³ = 840440921 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 840440891 and 840440900.

It is not a weakly prime, because it can be changed into another prime (840440921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420220464 + 420220465.

It is an arithmetic number, because the mean of its divisors is an integer number (420220465).

Almost surely, 2^840440929 is an apocalyptic number.

It is an amenable number.

840440929 is a deficient number, since it is larger than the sum of its proper divisors (1).

840440929 is an equidigital number, since it uses as much as digits as its factorization.

840440929 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82944, while the sum is 40.

The square root of 840440929 is about 28990.3592423412. The cubic root of 840440929 is about 943.7038598906.

The spelling of 840440929 in words is "eight hundred forty million, four hundred forty thousand, nine hundred twenty-nine".