166853503681 has 4 divisors (see below), whose sum is σ = 166855144192. Its totient is φ = 166851863172.

The previous prime is 166853503651. The next prime is 166853503699. The reversal of 166853503681 is 186305358661.

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 a cyclic number.

It is not a de Polignac number, because 166853503681 - 2¹³ = 166853495489 is a prime.

It is a super-2 number, since 2×166853503681² (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 (166853503601) 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, 656841 + ... + 874726.

It is an arithmetic number, because the mean of its divisors is an integer number (41713786048).

Almost surely, 2^166853503681 is an apocalyptic number.

It is an amenable number.

166853503681 is a deficient number, since it is larger than the sum of its proper divisors (1640511).

166853503681 is a wasteful number, since it uses less digits than its factorization.

166853503681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1640510.

The product of its (nonzero) digits is 3110400, while the sum is 52.

The spelling of 166853503681 in words is "one hundred sixty-six billion, eight hundred fifty-three million, five hundred three thousand, six hundred eighty-one".