21143625 has 16 divisors (see below), whose sum is σ = 35183616. Its totient is φ = 11276400.

The previous prime is 21143623. The next prime is 21143651. The reversal of 21143625 is 52634112.

It is not a de Polignac number, because 21143625 - 2¹ = 21143623 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21143595 and 21143604.

It is not an unprimeable number, because it can be changed into a prime (21143623) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27817 + ... + 28566.

It is an arithmetic number, because the mean of its divisors is an integer number (2198976).

Almost surely, 2^21143625 is an apocalyptic number.

21143625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21143625 is a deficient number, since it is larger than the sum of its proper divisors (14039991).

21143625 is an equidigital number, since it uses as much as digits as its factorization.

21143625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56401 (or 56391 counting only the distinct ones).

The product of its digits is 1440, while the sum is 24.

The square root of 21143625 is about 4598.2197642131. The cubic root of 21143625 is about 276.5199581856.

Adding to 21143625 its reverse (52634112), we get a palindrome (73777737).

The spelling of 21143625 in words is "twenty-one million, one hundred forty-three thousand, six hundred twenty-five".