40021680 has 80 divisors (see below), whose sum is σ = 125349120. Its totient is φ = 10562304.

The previous prime is 40021661. The next prime is 40021703. The reversal of 40021680 is 8612004.

It is a tau number, because it is divible by the number of its divisors (80).

40021680 is a modest number, since divided by 21680 gives 400 as remainder.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23911 + ... + 25529.

It is an arithmetic number, because the mean of its divisors is an integer number (1566864).

Almost surely, 2^40021680 is an apocalyptic number.

40021680 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 40021680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62674560).

40021680 is an abundant number, since it is smaller than the sum of its proper divisors (85327440).

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

40021680 is a wasteful number, since it uses less digits than its factorization.

40021680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1738 (or 1732 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 40021680 is about 6326.2690426507. The cubic root of 40021680 is about 342.0569653067.

Adding to 40021680 its reverse (8612004), we get a palindrome (48633684).

The spelling of 40021680 in words is "forty million, twenty-one thousand, six hundred eighty".