21141440 has 28 divisors (see below), whose sum is σ = 50343816. Its totient is φ = 8456448.

The previous prime is 21141437. The next prime is 21141451. The reversal of 21141440 is 4414112.

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32714 + ... + 33353.

Almost surely, 2^21141440 is an apocalyptic number.

21141440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21141440 is an abundant number, since it is smaller than the sum of its proper divisors (29202376).

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

21141440 is an equidigital number, since it uses as much as digits as its factorization.

21141440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66084 (or 66074 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 21141440 is about 4597.9821661246. The cubic root of 21141440 is about 276.5104325890.

Adding to 21141440 its reverse (4414112), we get a palindrome (25555552).

The spelling of 21141440 in words is "twenty-one million, one hundred forty-one thousand, four hundred forty".