21041025 has 12 divisors (see below), whose sum is σ = 34787952. Its totient is φ = 11221840.

The previous prime is 21041011. The next prime is 21041029. The reversal of 21041025 is 52014012.

It is not a de Polignac number, because 21041025 - 2¹⁰ = 21040001 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a junction number, because it is equal to n+sod(n) for n = 21040995 and 21041013.

It is not an unprimeable number, because it can be changed into a prime (21041029) 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, 140199 + ... + 140348.

It is an arithmetic number, because the mean of its divisors is an integer number (2898996).

Almost surely, 2^21041025 is an apocalyptic number.

21041025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21041025 is a deficient number, since it is larger than the sum of its proper divisors (13746927).

21041025 is a wasteful number, since it uses less digits than its factorization.

21041025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280560 (or 280555 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 21041025 is about 4587.0497054207. The cubic root of 21041025 is about 276.0719592878.

Adding to 21041025 its reverse (52014012), we get a palindrome (73055037).

The spelling of 21041025 in words is "twenty-one million, forty-one thousand, twenty-five".