1020400039 has 2 divisors, whose sum is σ = 1020400040. Its totient is φ = 1020400038.

The previous prime is 1020400021. The next prime is 1020400067. The reversal of 1020400039 is 9300040201.

1020400039 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1020400039 - 2⁷ = 1020399911 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1020399989 and 1020400025.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1020400099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510200019 + 510200020.

It is an arithmetic number, because the mean of its divisors is an integer number (510200020).

Almost surely, 2^1020400039 is an apocalyptic number.

1020400039 is a deficient number, since it is larger than the sum of its proper divisors (1).

1020400039 is an equidigital number, since it uses as much as digits as its factorization.

1020400039 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 1020400039 is about 31943.7010848774. The cubic root of 1020400039 is about 1006.7542898573.

The spelling of 1020400039 in words is "one billion, twenty million, four hundred thousand, thirty-nine".