217621317001 has 9 divisors (see below), whose sum is σ = 239209236903. Its totient is φ = 197832895920.

The previous prime is 217621316981. The next prime is 217621317047. The reversal of 217621317001 is 100713126712.

The square root of 217621317001 is 466499.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 150000515401 + 67620801600 = 387299^2 + 260040^2 .

It is not a de Polignac number, because 217621317001 - 2¹⁹ = 217620792713 is a prime.

It is a super-2 number, since 2×217621317001² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217621317071) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5110285 + ... + 5152693.

Almost surely, 2^217621317001 is an apocalyptic number.

217621317001 is the 466499-th square number.

217621317001 is the 233250-th centered octagonal number.

It is an amenable number.

217621317001 is a deficient number, since it is larger than the sum of its proper divisors (21587919902).

217621317001 is an frugal number, since it uses more digits than its factorization.

217621317001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84840 (or 42420 counting only the distinct ones).

The product of its (nonzero) digits is 3528, while the sum is 31.

The spelling of 217621317001 in words is "two hundred seventeen billion, six hundred twenty-one million, three hundred seventeen thousand, one".