40338391 has 4 divisors (see below), whose sum is σ = 41729400. Its totient is φ = 38947384.

The previous prime is 40338379. The next prime is 40338407. The reversal of 40338391 is 19383304.

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

It is a cyclic number.

It is not a de Polignac number, because 40338391 - 2¹⁷ = 40207319 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40338341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 695461 + ... + 695518.

It is an arithmetic number, because the mean of its divisors is an integer number (10432350).

Almost surely, 2^40338391 is an apocalyptic number.

40338391 is a deficient number, since it is larger than the sum of its proper divisors (1391009).

40338391 is a wasteful number, since it uses less digits than its factorization.

40338391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1391008.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 40338391 is about 6351.2511365872. The cubic root of 40338391 is about 342.9568832916.

The spelling of 40338391 in words is "forty million, three hundred thirty-eight thousand, three hundred ninety-one".