21259325 has 6 divisors (see below), whose sum is σ = 26361594. Its totient is φ = 17007440.

The previous prime is 21259321. The next prime is 21259327. The reversal of 21259325 is 52395212.

It can be written as a sum of positive squares in 3 ways, for example, as 7279204 + 13980121 = 2698^2 + 3739^2 .

It is not a de Polignac number, because 21259325 - 2² = 21259321 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21259321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 425162 + ... + 425211.

It is an arithmetic number, because the mean of its divisors is an integer number (4393599).

Almost surely, 2^21259325 is an apocalyptic number.

21259325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21259325 is a deficient number, since it is larger than the sum of its proper divisors (5102269).

21259325 is an equidigital number, since it uses as much as digits as its factorization.

21259325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850383 (or 850378 counting only the distinct ones).

The product of its digits is 5400, while the sum is 29.

The square root of 21259325 is about 4610.7835559696. The cubic root of 21259325 is about 277.0234224526.

The spelling of 21259325 in words is "twenty-one million, two hundred fifty-nine thousand, three hundred twenty-five".