217072913 has 4 divisors (see below), whose sum is σ = 217198080. Its totient is φ = 216947748.

The previous prime is 217072907. The next prime is 217072939. The reversal of 217072913 is 319270712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 217072913 - 2⁸ = 217072657 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 217072913.

It is not an unprimeable number, because it can be changed into a prime (217071913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59945 + ... + 63462.

It is an arithmetic number, because the mean of its divisors is an integer number (54299520).

Almost surely, 2^217072913 is an apocalyptic number.

It is an amenable number.

217072913 is a deficient number, since it is larger than the sum of its proper divisors (125167).

217072913 is a wasteful number, since it uses less digits than its factorization.

217072913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125166.

The product of its (nonzero) digits is 5292, while the sum is 32.

The square root of 217072913 is about 14733.3944832818. The cubic root of 217072913 is about 600.9917976221.

The spelling of 217072913 in words is "two hundred seventeen million, seventy-two thousand, nine hundred thirteen".