1020400005 has 16 divisors (see below), whose sum is σ = 1672461504. Its totient is φ = 530939520.

The previous prime is 1020399983. The next prime is 1020400021. The reversal of 1020400005 is 5000040201.

It is not a de Polignac number, because 1020400005 - 2⁹ = 1020399493 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 828979 + ... + 830208.

It is an arithmetic number, because the mean of its divisors is an integer number (104528844).

Almost surely, 2^1020400005 is an apocalyptic number.

1020400005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1020400005 is a deficient number, since it is larger than the sum of its proper divisors (652061499).

1020400005 is a wasteful number, since it uses less digits than its factorization.

1020400005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1659236.

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 1020400005 is about 31943.7005526911. The cubic root of 1020400005 is about 1006.7542786755.

Adding to 1020400005 its reverse (5000040201), we get a palindrome (6020440206).

The spelling of 1020400005 in words is "one billion, twenty million, four hundred thousand, five".