1040139805 has 4 divisors (see below), whose sum is σ = 1248167772. Its totient is φ = 832111840.

The previous prime is 1040139799. The next prime is 1040139889. The reversal of 1040139805 is 5089310401.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5089310401 = 7 ⋅727044343.

It can be written as a sum of positive squares in 2 ways, for example, as 130393561 + 909746244 = 11419^2 + 30162^2 .

It is not a de Polignac number, because 1040139805 - 2⁵ = 1040139773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104013976 + ... + 104013985.

It is an arithmetic number, because the mean of its divisors is an integer number (312041943).

Almost surely, 2^1040139805 is an apocalyptic number.

It is an amenable number.

1040139805 is a deficient number, since it is larger than the sum of its proper divisors (208027967).

1040139805 is an equidigital number, since it uses as much as digits as its factorization.

1040139805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208027966.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 1040139805 is about 32251.1985048618. The cubic root of 1040139805 is about 1013.2048007445.

The spelling of 1040139805 in words is "one billion, forty million, one hundred thirty-nine thousand, eight hundred five".