215972065 has 4 divisors (see below), whose sum is σ = 259166484. Its totient is φ = 172777648.

The previous prime is 215972039. The next prime is 215972083. The reversal of 215972065 is 560279512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 129686544 + 86285521 = 11388^2 + 9289^2 .

It is a cyclic number.

It is not a de Polignac number, because 215972065 - 2⁷ = 215971937 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 21597202 + ... + 21597211.

It is an arithmetic number, because the mean of its divisors is an integer number (64791621).

Almost surely, 2^215972065 is an apocalyptic number.

It is an amenable number.

215972065 is a deficient number, since it is larger than the sum of its proper divisors (43194419).

215972065 is an equidigital number, since it uses as much as digits as its factorization.

215972065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43194418.

The product of its (nonzero) digits is 37800, while the sum is 37.

The square root of 215972065 is about 14695.9880579701. The cubic root of 215972065 is about 599.9741331441.

The spelling of 215972065 in words is "two hundred fifteen million, nine hundred seventy-two thousand, sixty-five".