40381639 has 4 divisors (see below), whose sum is σ = 40539024. Its totient is φ = 40224256.

The previous prime is 40381619. The next prime is 40381657. The reversal of 40381639 is 93618304.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40381639 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 (40381609) 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, 78307 + ... + 78820.

It is an arithmetic number, because the mean of its divisors is an integer number (10134756).

Almost surely, 2^40381639 is an apocalyptic number.

40381639 is a deficient number, since it is larger than the sum of its proper divisors (157385).

40381639 is a wasteful number, since it uses less digits than its factorization.

40381639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157384.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 40381639 is about 6354.6549080182. The cubic root of 40381639 is about 343.0794043061.

The spelling of 40381639 in words is "forty million, three hundred eighty-one thousand, six hundred thirty-nine".