171685664442 has 24 divisors (see below), whose sum is σ = 371997913716. Its totient is φ = 57226661376.

The previous prime is 171685664431. The next prime is 171685664443. The reversal of 171685664442 is 244466586171.

171685664442 is a `hidden beast` number, since 1 + 71 + 6 + 8 + 566 + 4 + 4 + 4 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 109500766281 + 62184898161 = 330909^2 + 249369^2 .

It is not an unprimeable number, because it can be changed into a prime (171685664443) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 468568 + ... + 750284.

Almost surely, 2^171685664442 is an apocalyptic number.

171685664442 is an abundant number, since it is smaller than the sum of its proper divisors (200312249274).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

171685664442 is a wasteful number, since it uses less digits than its factorization.

171685664442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315582 (or 315579 counting only the distinct ones).

The product of its digits is 7741440, while the sum is 54.

The spelling of 171685664442 in words is "one hundred seventy-one billion, six hundred eighty-five million, six hundred sixty-four thousand, four hundred forty-two".