212451221 has 4 divisors (see below), whose sum is σ = 213723552. Its totient is φ = 211178892.

The previous prime is 212451167. The next prime is 212451223. The reversal of 212451221 is 122154212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 212451221 - 2¹⁴ = 212434837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212451193 and 212451202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212451223) 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 3 ways as a sum of consecutive naturals, for example, 635915 + ... + 636248.

It is an arithmetic number, because the mean of its divisors is an integer number (53430888).

Almost surely, 2^212451221 is an apocalyptic number.

It is an amenable number.

212451221 is a deficient number, since it is larger than the sum of its proper divisors (1272331).

212451221 is a wasteful number, since it uses less digits than its factorization.

212451221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1272330.

The product of its digits is 320, while the sum is 20.

The square root of 212451221 is about 14575.7065351907. The cubic root of 212451221 is about 596.6959321427.

The spelling of 212451221 in words is "two hundred twelve million, four hundred fifty-one thousand, two hundred twenty-one".