21053025 has 36 divisors (see below), whose sum is σ = 43098432. Its totient is φ = 9623520.

The previous prime is 21053017. The next prime is 21053041. The reversal of 21053025 is 52035012.

It is a happy number.

It is not a de Polignac number, because 21053025 - 2³ = 21053017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21052989 and 21053007.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 5109 + ... + 8258.

Almost surely, 2^21053025 is an apocalyptic number.

21053025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21053025 is an abundant number, since it is smaller than the sum of its proper divisors (22045407).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21053025 is a wasteful number, since it uses less digits than its factorization.

21053025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13390 (or 13382 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 21053025 is about 4588.3575492762. The cubic root of 21053025 is about 276.1244319204.

Adding to 21053025 its reverse (52035012), we get a palindrome (73088037).

It can be divided in two parts, 210 and 53025, that added together give a palindrome (53235).

The spelling of 21053025 in words is "twenty-one million, fifty-three thousand, twenty-five".