21143325 has 96 divisors (see below), whose sum is σ = 44568576. Its totient is φ = 8616960.

The previous prime is 21143293. The next prime is 21143327. The reversal of 21143325 is 52334112.

It is not a de Polignac number, because 21143325 - 2⁵ = 21143293 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21143327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 205224 + ... + 205326.

It is an arithmetic number, because the mean of its divisors is an integer number (464256).

Almost surely, 2^21143325 is an apocalyptic number.

21143325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21143325 is an abundant number, since it is smaller than the sum of its proper divisors (23425251).

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

21143325 is a wasteful number, since it uses less digits than its factorization.

21143325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163 (or 158 counting only the distinct ones).

The product of its digits is 720, while the sum is 21.

The square root of 21143325 is about 4598.1871427770. The cubic root of 21143325 is about 276.5186503622.

Adding to 21143325 its reverse (52334112), we get a palindrome (73477437).

It can be divided in two parts, 211433 and 25, that multiplied together give a palindrome (5285825).

The spelling of 21143325 in words is "twenty-one million, one hundred forty-three thousand, three hundred twenty-five".