21123325 has 12 divisors (see below), whose sum is σ = 26332020. Its totient is φ = 16808960.

The previous prime is 21123313. The next prime is 21123331. The reversal of 21123325 is 52332112.

It can be written as a sum of positive squares in 6 ways, for example, as 3992004 + 17131321 = 1998^2 + 4139^2 .

It is not a de Polignac number, because 21123325 - 2⁵ = 21123293 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2781 + ... + 7069.

It is an arithmetic number, because the mean of its divisors is an integer number (2194335).

Almost surely, 2^21123325 is an apocalyptic number.

21123325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21123325 is a deficient number, since it is larger than the sum of its proper divisors (5208695).

21123325 is a wasteful number, since it uses less digits than its factorization.

21123325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4496 (or 4491 counting only the distinct ones).

The product of its digits is 360, while the sum is 19.

The square root of 21123325 is about 4596.0118581222. The cubic root of 21123325 is about 276.4314342204.

Adding to 21123325 its reverse (52332112), we get a palindrome (73455437).

It can be divided in two parts, 211233 and 25, that multiplied together give a palindrome (5280825).

The spelling of 21123325 in words is "twenty-one million, one hundred twenty-three thousand, three hundred twenty-five".