40251809 has 8 divisors (see below), whose sum is σ = 43417920. Its totient is φ = 37095696.

The previous prime is 40251803. The next prime is 40251829. The reversal of 40251809 is 90815204.

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 40251809 - 2⁴ = 40251793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (40251803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7322 + ... + 11580.

It is an arithmetic number, because the mean of its divisors is an integer number (5427240).

Almost surely, 2^40251809 is an apocalyptic number.

It is an amenable number.

40251809 is a deficient number, since it is larger than the sum of its proper divisors (3166111).

40251809 is a wasteful number, since it uses less digits than its factorization.

40251809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4999.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 40251809 is about 6344.4313377954. The cubic root of 40251809 is about 342.7113342219.

The spelling of 40251809 in words is "forty million, two hundred fifty-one thousand, eight hundred nine".