1638135145 has 16 divisors (see below), whose sum is σ = 1975057488. Its totient is φ = 1304328960.

The previous prime is 1638135137. The next prime is 1638135173. The reversal of 1638135145 is 5415318361.

It can be written as a sum of positive squares in 8 ways, for example, as 112529664 + 1525605481 = 10608^2 + 39059^2 .

It is not a de Polignac number, because 1638135145 - 2³ = 1638135137 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1740375 + ... + 1741315.

It is an arithmetic number, because the mean of its divisors is an integer number (123441093).

Almost surely, 2^1638135145 is an apocalyptic number.

It is an amenable number.

1638135145 is a deficient number, since it is larger than the sum of its proper divisors (336922343).

1638135145 is an equidigital number, since it uses as much as digits as its factorization.

1638135145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2220.

The product of its digits is 43200, while the sum is 37.

The square root of 1638135145 is about 40473.8822575745. The cubic root of 1638135145 is about 1178.8265517821.

The spelling of 1638135145 in words is "one billion, six hundred thirty-eight million, one hundred thirty-five thousand, one hundred forty-five".