217990208631 has 16 divisors (see below), whose sum is σ = 313247535104. Its totient is φ = 134046697824.

The previous prime is 217990208629. The next prime is 217990208647. The reversal of 217990208631 is 136802099712.

It is not a de Polignac number, because 217990208631 - 2¹ = 217990208629 is a prime.

It is a super-2 number, since 2×217990208631² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217990201631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2054311 + ... + 2157816.

It is an arithmetic number, because the mean of its divisors is an integer number (19577970944).

Almost surely, 2^217990208631 is an apocalyptic number.

217990208631 is a deficient number, since it is larger than the sum of its proper divisors (95257326473).

217990208631 is a wasteful number, since it uses less digits than its factorization.

217990208631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4213470.

The product of its (nonzero) digits is 326592, while the sum is 48.

The spelling of 217990208631 in words is "two hundred seventeen billion, nine hundred ninety million, two hundred eight thousand, six hundred thirty-one".