212661225 has 54 divisors (see below), whose sum is σ = 443110590. Its totient is φ = 97211520.

The previous prime is 212661221. The next prime is 212661227. The reversal of 212661225 is 522166212.

212661225 is a `hidden beast` number, since 2 + 1 + 26 + 612 + 25 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 25190361 + 187470864 = 5019^2 + 13692^2 .

It is not a de Polignac number, because 212661225 - 2² = 212661221 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (212661221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 1381 + ... + 20669.

Almost surely, 2^212661225 is an apocalyptic number.

212661225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

212661225 is an abundant number, since it is smaller than the sum of its proper divisors (230449365).

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

212661225 is a wasteful number, since it uses less digits than its factorization.

212661225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19319 (or 19304 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 212661225 is about 14582.9086604833. The cubic root of 212661225 is about 596.8924749322.

The spelling of 212661225 in words is "two hundred twelve million, six hundred sixty-one thousand, two hundred twenty-five".