40404394 has 4 divisors (see below), whose sum is σ = 60606594. Its totient is φ = 20202196.

The previous prime is 40404389. The next prime is 40404409. The reversal of 40404394 is 49340404.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 22231225 + 18173169 = 4715^2 + 4263^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 10101097 + ... + 10101100.

Almost surely, 2^40404394 is an apocalyptic number.

40404394 is a deficient number, since it is larger than the sum of its proper divisors (20202200).

40404394 is a wasteful number, since it uses less digits than its factorization.

40404394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20202199.

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 40404394 is about 6356.4450756693. The cubic root of 40404394 is about 343.1438338020.

Adding to 40404394 its reverse (49340404), we get a palindrome (89744798).

The spelling of 40404394 in words is "forty million, four hundred four thousand, three hundred ninety-four".