21401140 has 24 divisors (see below), whose sum is σ = 45616032. Its totient is φ = 8432160.

The previous prime is 21401137. The next prime is 21401203. The reversal of 21401140 is 4110412.

It is a self number, because there is not a number n which added to its sum of digits gives 21401140.

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 7 ways as a sum of consecutive naturals, for example, 6646 + ... + 9325.

It is an arithmetic number, because the mean of its divisors is an integer number (1900668).

Almost surely, 2^21401140 is an apocalyptic number.

21401140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21401140 is an abundant number, since it is smaller than the sum of its proper divisors (24214892).

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

21401140 is a wasteful number, since it uses less digits than its factorization.

21401140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16047 (or 16045 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21401140 is about 4626.1366170921. The cubic root of 21401140 is about 277.6380397007.

Adding to 21401140 its reverse (4110412), we get a palindrome (25511552).

The spelling of 21401140 in words is "twenty-one million, four hundred one thousand, one hundred forty".