21203425 has 12 divisors (see below), whose sum is σ = 26375296. Its totient is φ = 16909200.

The previous prime is 21203419. The next prime is 21203431. The reversal of 21203425 is 52430212.

It is an interprime number because it is at equal distance from previous prime (21203419) and next prime (21203431).

It is not a de Polignac number, because 21203425 - 2¹³ = 21195233 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 8020 + ... + 10330.

Almost surely, 2^21203425 is an apocalyptic number.

21203425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21203425 is a deficient number, since it is larger than the sum of its proper divisors (5171871).

21203425 is a wasteful number, since it uses less digits than its factorization.

21203425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2688 (or 2683 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21203425 is about 4604.7176895006. The cubic root of 21203425 is about 276.7804043578.

Adding to 21203425 its reverse (52430212), we get a palindrome (73633637).

The spelling of 21203425 in words is "twenty-one million, two hundred three thousand, four hundred twenty-five".