40409906 has 4 divisors (see below), whose sum is σ = 60614862. Its totient is φ = 20204952.

The previous prime is 40409891. The next prime is 40409917. The reversal of 40409906 is 60990404.

It is a happy number.

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., 31259281 + 9150625 = 5591^2 + 3025^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10102475 + ... + 10102478.

Almost surely, 2^40409906 is an apocalyptic number.

40409906 is a deficient number, since it is larger than the sum of its proper divisors (20204956).

40409906 is a wasteful number, since it uses less digits than its factorization.

40409906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20204955.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 40409906 is about 6356.8786365637. The cubic root of 40409906 is about 343.1594370786.

The spelling of 40409906 in words is "forty million, four hundred nine thousand, nine hundred six".