212720665 has 8 divisors (see below), whose sum is σ = 259591680. Its totient is φ = 167291952.

The previous prime is 212720663. The next prime is 212720687. The reversal of 212720665 is 566027212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212720665 - 2¹ = 212720663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (212720663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 360249 + ... + 360838.

It is an arithmetic number, because the mean of its divisors is an integer number (32448960).

Almost surely, 2^212720665 is an apocalyptic number.

It is an amenable number.

212720665 is a deficient number, since it is larger than the sum of its proper divisors (46871015).

212720665 is an equidigital number, since it uses as much as digits as its factorization.

212720665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721151.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 212720665 is about 14584.9465202996. The cubic root of 212720665 is about 596.9480813451.

Adding to 212720665 its reverse (566027212), we get a palindrome (778747877).

The spelling of 212720665 in words is "two hundred twelve million, seven hundred twenty thousand, six hundred sixty-five".