40021440 has 112 divisors (see below), whose sum is σ = 129917952. Its totient is φ = 10433536.

The previous prime is 40021427. The next prime is 40021459. The reversal of 40021440 is 4412004.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 44677 + ... + 45563.

Almost surely, 2^40021440 is an apocalyptic number.

40021440 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 40021440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64958976).

40021440 is an abundant number, since it is smaller than the sum of its proper divisors (89896512).

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

40021440 is a wasteful number, since it uses less digits than its factorization.

40021440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 954 (or 944 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 40021440 is about 6326.2500740960. The cubic root of 40021440 is about 342.0562815620.

Adding to 40021440 its reverse (4412004), we get a palindrome (44433444).

The spelling of 40021440 in words is "forty million, twenty-one thousand, four hundred forty".