212720417 has 12 divisors (see below), whose sum is σ = 266485716. Its totient is φ = 168305760.

The previous prime is 212720393. The next prime is 212720471. The reversal of 212720417 is 714027212.

It can be written as a sum of positive squares in 2 ways, for example, as 55368481 + 157351936 = 7441^2 + 12544^2 .

It is not a de Polignac number, because 212720417 - 2¹⁰ = 212719393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (212720477) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 166334 + ... + 167607.

It is an arithmetic number, because the mean of its divisors is an integer number (22207143).

Almost surely, 2^212720417 is an apocalyptic number.

It is an amenable number.

212720417 is a deficient number, since it is larger than the sum of its proper divisors (53765299).

212720417 is a wasteful number, since it uses less digits than its factorization.

212720417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333968 (or 333961 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 26.

The square root of 212720417 is about 14584.9380183805. The cubic root of 212720417 is about 596.9478493614.

Adding to 212720417 its reverse (714027212), we get a palindrome (926747629).

The spelling of 212720417 in words is "two hundred twelve million, seven hundred twenty thousand, four hundred seventeen".