21053140 has 48 divisors (see below), whose sum is σ = 49291200. Its totient is φ = 7506432.

The previous prime is 21053129. The next prime is 21053173. The reversal of 21053140 is 4135012.

It is a congruent number.

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, 4831 + ... + 8089.

It is an arithmetic number, because the mean of its divisors is an integer number (1026900).

Almost surely, 2^21053140 is an apocalyptic number.

21053140 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 21053140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24645600).

21053140 is an abundant number, since it is smaller than the sum of its proper divisors (28238060).

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

21053140 is a wasteful number, since it uses less digits than its factorization.

21053140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3304 (or 3302 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21053140 is about 4588.3700809765. The cubic root of 21053140 is about 276.1249346866.

Adding to 21053140 its reverse (4135012), we get a palindrome (25188152).

The spelling of 21053140 in words is "twenty-one million, fifty-three thousand, one hundred forty".