21088425 has 24 divisors (see below), whose sum is σ = 35015616. Its totient is φ = 11199040.

The previous prime is 21088421. The next prime is 21088439. The reversal of 21088425 is 52488012.

It is not a de Polignac number, because 21088425 - 2² = 21088421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21088392 and 21088401.

It is not an unprimeable number, because it can be changed into a prime (21088421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23332 + ... + 24218.

It is an arithmetic number, because the mean of its divisors is an integer number (1458984).

Almost surely, 2^21088425 is an apocalyptic number.

21088425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21088425 is a deficient number, since it is larger than the sum of its proper divisors (13927191).

21088425 is a wasteful number, since it uses less digits than its factorization.

21088425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1217 (or 1212 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 21088425 is about 4592.2135185551. The cubic root of 21088425 is about 276.2791101092.

The spelling of 21088425 in words is "twenty-one million, eighty-eight thousand, four hundred twenty-five".