40391845 has 16 divisors (see below), whose sum is σ = 52521840. Its totient is φ = 29819712.

The previous prime is 40391843. The next prime is 40391873. The reversal of 40391845 is 54819304.

It can be written as a sum of positive squares in 8 ways, for example, as 24383844 + 16008001 = 4938^2 + 4001^2 .

It is not a de Polignac number, because 40391845 - 2¹ = 40391843 is a prime.

It is a super-2 number, since 2×40391845² = 3263002285008050, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 40391845.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40391843) 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 in 15 ways as a sum of consecutive naturals, for example, 9147 + ... + 12823.

It is an arithmetic number, because the mean of its divisors is an integer number (3282615).

Almost surely, 2^40391845 is an apocalyptic number.

It is an amenable number.

40391845 is a deficient number, since it is larger than the sum of its proper divisors (12129995).

40391845 is an equidigital number, since it uses as much as digits as its factorization.

40391845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3721 (or 3695 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 40391845 is about 6355.4578906637. The cubic root of 40391845 is about 343.1083050106.

The spelling of 40391845 in words is "forty million, three hundred ninety-one thousand, eight hundred forty-five".