210021225 has 12 divisors (see below), whose sum is σ = 347235216. Its totient is φ = 112011280.

The previous prime is 210021209. The next prime is 210021241. The reversal of 210021225 is 522120012.

It is an interprime number because it is at equal distance from previous prime (210021209) and next prime (210021241).

It is not a de Polignac number, because 210021225 - 2⁴ = 210021209 is a prime.

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

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1400067 + ... + 1400216.

It is an arithmetic number, because the mean of its divisors is an integer number (28936268).

Almost surely, 2^210021225 is an apocalyptic number.

210021225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

210021225 is a deficient number, since it is larger than the sum of its proper divisors (137213991).

210021225 is a wasteful number, since it uses less digits than its factorization.

210021225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2800296 (or 2800291 counting only the distinct ones).

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

The square root of 210021225 is about 14492.1090597608. The cubic root of 210021225 is about 594.4122199578.

Adding to 210021225 its reverse (522120012), we get a palindrome (732141237).

The spelling of 210021225 in words is "two hundred ten million, twenty-one thousand, two hundred twenty-five".