40840781 has 8 divisors (see below), whose sum is σ = 41616384. Its totient is φ = 40068720.

The previous prime is 40840777. The next prime is 40840829. The reversal of 40840781 is 18704804.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 40840781 - 2² = 40840777 is a prime.

It is a super-2 number, since 2×40840781² = 3335938785379922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40840741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36476 + ... + 37578.

It is an arithmetic number, because the mean of its divisors is an integer number (5202048).

Almost surely, 2^40840781 is an apocalyptic number.

It is an amenable number.

40840781 is a deficient number, since it is larger than the sum of its proper divisors (775603).

40840781 is a wasteful number, since it uses less digits than its factorization.

40840781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1771.

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 40840781 is about 6390.6792283763. The cubic root of 40840781 is about 344.3747858866.

The spelling of 40840781 in words is "forty million, eight hundred forty thousand, seven hundred eighty-one".