21110025 has 24 divisors (see below), whose sum is σ = 35431264. Its totient is φ = 11088000.

The previous prime is 21109987. The next prime is 21110027. The reversal of 21110025 is 52001112.

It is not a de Polignac number, because 21110025 - 2⁷ = 21109897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21110027) 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, 2925 + ... + 7125.

Almost surely, 2^21110025 is an apocalyptic number.

21110025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21110025 is a deficient number, since it is larger than the sum of its proper divisors (14321239).

21110025 is a wasteful number, since it uses less digits than its factorization.

21110025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4281 (or 4276 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 21110025 is about 4594.5647236708. The cubic root of 21110025 is about 276.3734050043.

Adding to 21110025 its reverse (52001112), we get a palindrome (73111137).

The spelling of 21110025 in words is "twenty-one million, one hundred ten thousand, twenty-five".