216973529 has 4 divisors (see below), whose sum is σ = 218355684. Its totient is φ = 215591376.

The previous prime is 216973501. The next prime is 216973541. The reversal of 216973529 is 925379612.

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 157452304 + 59521225 = 12548^2 + 7715^2 .

It is a cyclic number.

It is not a de Polignac number, because 216973529 - 2¹⁶ = 216907993 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 216973529.

It is not an unprimeable number, because it can be changed into a prime (216973129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 690842 + ... + 691155.

It is an arithmetic number, because the mean of its divisors is an integer number (54588921).

Almost surely, 2^216973529 is an apocalyptic number.

It is an amenable number.

216973529 is a deficient number, since it is larger than the sum of its proper divisors (1382155).

216973529 is a wasteful number, since it uses less digits than its factorization.

216973529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1382154.

The product of its digits is 204120, while the sum is 44.

The square root of 216973529 is about 14730.0213509689. The cubic root of 216973529 is about 600.9000648710.

The spelling of 216973529 in words is "two hundred sixteen million, nine hundred seventy-three thousand, five hundred twenty-nine".