21370425 has 24 divisors (see below), whose sum is σ = 35768544. Its totient is φ = 11256960.

The previous prime is 21370409. The next prime is 21370429. The reversal of 21370425 is 52407312.

It is not a de Polignac number, because 21370425 - 2⁴ = 21370409 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21370395 and 21370404.

It is not an unprimeable number, because it can be changed into a prime (21370429) 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 23 ways as a sum of consecutive naturals, for example, 4509 + ... + 7941.

It is an arithmetic number, because the mean of its divisors is an integer number (1490356).

Almost surely, 2^21370425 is an apocalyptic number.

21370425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21370425 is a deficient number, since it is larger than the sum of its proper divisors (14398119).

21370425 is a wasteful number, since it uses less digits than its factorization.

21370425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3529 (or 3524 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 21370425 is about 4622.8157004146. The cubic root of 21370425 is about 277.5051537067.

Adding to 21370425 its reverse (52407312), we get a palindrome (73777737).

The spelling of 21370425 in words is "twenty-one million, three hundred seventy thousand, four hundred twenty-five".