217493900639 has 4 divisors (see below), whose sum is σ = 219526554024. Its totient is φ = 215461247256.

The previous prime is 217493900623. The next prime is 217493900653. The reversal of 217493900639 is 936009394712.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 217493900639 - 2⁴ = 217493900623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217493900699) 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, 1016326532 + ... + 1016326745.

It is an arithmetic number, because the mean of its divisors is an integer number (54881638506).

Almost surely, 2^217493900639 is an apocalyptic number.

217493900639 is a deficient number, since it is larger than the sum of its proper divisors (2032653385).

217493900639 is a wasteful number, since it uses less digits than its factorization.

217493900639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2032653384.

The product of its (nonzero) digits is 2204496, while the sum is 53.

The spelling of 217493900639 in words is "two hundred seventeen billion, four hundred ninety-three million, nine hundred thousand, six hundred thirty-nine".