21941040 has 80 divisors (see below), whose sum is σ = 74209536. Its totient is φ = 5318400.

The previous prime is 21941021. The next prime is 21941041. The reversal of 21941040 is 4014912.

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

It is a junction number, because it is equal to n+sod(n) for n = 21940998 and 21941016.

It is not an unprimeable number, because it can be changed into a prime (21941041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1516 + ... + 6795.

Almost surely, 2^21941040 is an apocalyptic number.

21941040 is a gapful number since it is divisible by the number (20) 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 21941040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37104768).

21941040 is an abundant number, since it is smaller than the sum of its proper divisors (52268496).

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

21941040 is a wasteful number, since it uses less digits than its factorization.

21941040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8338 (or 8332 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21941040 is about 4684.1263859977. The cubic root of 21941040 is about 279.9533936033.

Adding to 21941040 its reverse (4014912), we get a palindrome (25955952).

The spelling of 21941040 in words is "twenty-one million, nine hundred forty-one thousand, forty".