21230825 has 48 divisors (see below), whose sum is σ = 33747840. Its totient is φ = 12864000.

The previous prime is 21230801. The next prime is 21230827. The reversal of 21230825 is 52803212.

It is not a de Polignac number, because 21230825 - 2⁶ = 21230761 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21230825.

It is not an unprimeable number, because it can be changed into a prime (21230827) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 78791 + ... + 79059.

It is an arithmetic number, because the mean of its divisors is an integer number (703080).

Almost surely, 2^21230825 is an apocalyptic number.

21230825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21230825 is a deficient number, since it is larger than the sum of its proper divisors (12517015).

21230825 is a wasteful number, since it uses less digits than its factorization.

21230825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338 (or 333 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21230825 is about 4607.6919384872. The cubic root of 21230825 is about 276.8995756508.

The spelling of 21230825 in words is "twenty-one million, two hundred thirty thousand, eight hundred twenty-five".