212520665 has 32 divisors (see below), whose sum is σ = 298460160. Its totient is φ = 142272000.

The previous prime is 212520661. The next prime is 212520673. The reversal of 212520665 is 566025212.

It is not a de Polignac number, because 212520665 - 2² = 212520661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (212520661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 278885 + ... + 279645.

It is an arithmetic number, because the mean of its divisors is an integer number (9326880).

Almost surely, 2^212520665 is an apocalyptic number.

It is an amenable number.

212520665 is a deficient number, since it is larger than the sum of its proper divisors (85939495).

212520665 is a wasteful number, since it uses less digits than its factorization.

212520665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 953.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 212520665 is about 14578.0885235342. The cubic root of 212520665 is about 596.7609391250.

Adding to 212520665 its reverse (566025212), we get a palindrome (778545877).

The spelling of 212520665 in words is "two hundred twelve million, five hundred twenty thousand, six hundred sixty-five".