21143120 has 20 divisors (see below), whose sum is σ = 49157940. Its totient is φ = 8457216.

The previous prime is 21143113. The next prime is 21143137. The reversal of 21143120 is 2134112.

It can be written as a sum of positive squares in 2 ways, for example, as 2238016 + 18905104 = 1496^2 + 4348^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 21143095 and 21143104.

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, 132065 + ... + 132224.

It is an arithmetic number, because the mean of its divisors is an integer number (2457897).

Almost surely, 2^21143120 is an apocalyptic number.

21143120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21143120 is an abundant number, since it is smaller than the sum of its proper divisors (28014820).

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

21143120 is a wasteful number, since it uses less digits than its factorization.

21143120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264302 (or 264296 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21143120 is about 4598.1648513293. The cubic root of 21143120 is about 276.5177566758.

Adding to 21143120 its reverse (2134112), we get a palindrome (23277232).

The spelling of 21143120 in words is "twenty-one million, one hundred forty-three thousand, one hundred twenty".