21106025 has 12 divisors (see below), whose sum is σ = 26349504. Its totient is φ = 16770000.

The previous prime is 21105977. The next prime is 21106037. The reversal of 21106025 is 52060112.

It is not a de Polignac number, because 21106025 - 2⁸ = 21105769 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21105994 and 21106012.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 980 + ... + 6570.

It is an arithmetic number, because the mean of its divisors is an integer number (2195792).

Almost surely, 2^21106025 is an apocalyptic number.

21106025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21106025 is a deficient number, since it is larger than the sum of its proper divisors (5243479).

21106025 is a wasteful number, since it uses less digits than its factorization.

21106025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5752 (or 5747 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 21106025 is about 4594.1294061008. The cubic root of 21106025 is about 276.3559478411.

Adding to 21106025 its reverse (52060112), we get a palindrome (73166137).

The spelling of 21106025 in words is "twenty-one million, one hundred six thousand, twenty-five".