40391920 has 40 divisors (see below), whose sum is σ = 94860000. Its totient is φ = 15993600.

The previous prime is 40391903. The next prime is 40391927. The reversal of 40391920 is 2919304.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40391927) 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, 5581 + ... + 10579.

It is an arithmetic number, because the mean of its divisors is an integer number (2371500).

Almost surely, 2^40391920 is an apocalyptic number.

40391920 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 40391920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47430000).

40391920 is an abundant number, since it is smaller than the sum of its proper divisors (54468080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

40391920 is a wasteful number, since it uses less digits than its factorization.

40391920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5113 (or 5107 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 40391920 is about 6355.4637911013. The cubic root of 40391920 is about 343.1085173729.

The spelling of 40391920 in words is "forty million, three hundred ninety-one thousand, nine hundred twenty".