217960538997 has 4 divisors (see below), whose sum is σ = 290614052000. Its totient is φ = 145307025996.

The previous prime is 217960538993. The next prime is 217960539011. The reversal of 217960538997 is 799835069712.

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 not a de Polignac number, because 217960538997 - 2² = 217960538993 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 (217960538993) 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, 36326756497 + ... + 36326756502.

It is an arithmetic number, because the mean of its divisors is an integer number (72653513000).

Almost surely, 2^217960538997 is an apocalyptic number.

It is an amenable number.

217960538997 is a deficient number, since it is larger than the sum of its proper divisors (72653513003).

217960538997 is an equidigital number, since it uses as much as digits as its factorization.

217960538997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72653513002.

The product of its (nonzero) digits is 51438240, while the sum is 66.

The spelling of 217960538997 in words is "two hundred seventeen billion, nine hundred sixty million, five hundred thirty-eight thousand, nine hundred ninety-seven".