21461140 has 72 divisors (see below), whose sum is σ = 49512960. Its totient is φ = 7807488.

The previous prime is 21461137. The next prime is 21461173. The reversal of 21461140 is 4116412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 271621 + ... + 271699.

It is an arithmetic number, because the mean of its divisors is an integer number (687680).

Almost surely, 2^21461140 is an apocalyptic number.

21461140 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 21461140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24756480).

21461140 is an abundant number, since it is smaller than the sum of its proper divisors (28051820).

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

21461140 is a wasteful number, since it uses less digits than its factorization.

21461140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 21461140 is about 4632.6169710003. The cubic root of 21461140 is about 277.8972585854.

Adding to 21461140 its reverse (4116412), we get a palindrome (25577552).

The spelling of 21461140 in words is "twenty-one million, four hundred sixty-one thousand, one hundred forty".