40381643 has 4 divisors (see below), whose sum is σ = 40604928. Its totient is φ = 40158360.

The previous prime is 40381619. The next prime is 40381657. The reversal of 40381643 is 34618304.

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 40381643 - 2⁸ = 40381387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40381603) 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, 111371 + ... + 111732.

It is an arithmetic number, because the mean of its divisors is an integer number (10151232).

Almost surely, 2^40381643 is an apocalyptic number.

40381643 is a deficient number, since it is larger than the sum of its proper divisors (223285).

40381643 is a wasteful number, since it uses less digits than its factorization.

40381643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223284.

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 40381643 is about 6354.6552227481. The cubic root of 40381643 is about 343.0794156340.

Adding to 40381643 its reverse (34618304), we get a palindrome (74999947).

The spelling of 40381643 in words is "forty million, three hundred eighty-one thousand, six hundred forty-three".