217061661704 has 8 divisors (see below), whose sum is σ = 406990615710. Its totient is φ = 108530830848.

The previous prime is 217061661701. The next prime is 217061661721. The reversal of 217061661704 is 407166160712.

It can be written as a sum of positive squares in only one way, i.e., 179692905604 + 37368756100 = 423902^2 + 193310^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (217061661701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13566353849 + ... + 13566353864.

Almost surely, 2^217061661704 is an apocalyptic number.

It is an amenable number.

217061661704 is a deficient number, since it is larger than the sum of its proper divisors (189928954006).

217061661704 is a wasteful number, since it uses less digits than its factorization.

217061661704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27132707719 (or 27132707715 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 41.

The spelling of 217061661704 in words is "two hundred seventeen billion, sixty-one million, six hundred sixty-one thousand, seven hundred four".