21025425 has 12 divisors (see below), whose sum is σ = 34762160. Its totient is φ = 11213520.

The previous prime is 21025423. The next prime is 21025439. The reversal of 21025425 is 52452012.

It is a happy number.

It is not a de Polignac number, because 21025425 - 2¹ = 21025423 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21025423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 140095 + ... + 140244.

Almost surely, 2^21025425 is an apocalyptic number.

21025425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21025425 is a deficient number, since it is larger than the sum of its proper divisors (13736735).

21025425 is a wasteful number, since it uses less digits than its factorization.

21025425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280352 (or 280347 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 21025425 is about 4585.3489507343. The cubic root of 21025425 is about 276.0037150309.

Adding to 21025425 its reverse (52452012), we get a palindrome (73477437).

The spelling of 21025425 in words is "twenty-one million, twenty-five thousand, four hundred twenty-five".