40003920 has 120 divisors (see below), whose sum is σ = 146588832. Its totient is φ = 9696000.

The previous prime is 40003913. The next prime is 40003937. The reversal of 40003920 is 2930004.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 40003893 and 40003902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5395 + ... + 10445.

Almost surely, 2^40003920 is an apocalyptic number.

40003920 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 40003920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73294416).

40003920 is an abundant number, since it is smaller than the sum of its proper divisors (106584912).

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

40003920 is a wasteful number, since it uses less digits than its factorization.

40003920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5081 (or 5072 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 40003920 is about 6324.8652159552. The cubic root of 40003920 is about 342.0063608133.

Adding to 40003920 its reverse (2930004), we get a palindrome (42933924).

The spelling of 40003920 in words is "forty million, three thousand, nine hundred twenty".