172666917281 has 4 divisors (see below), whose sum is σ = 172670377152. Its totient is φ = 172663457412.

The previous prime is 172666917277. The next prime is 172666917287. The reversal of 172666917281 is 182719666271.

It is a happy number.

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 172666917281 - 2² = 172666917277 is a prime.

It is a super-2 number, since 2×172666917281² (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 (172666917287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1653965 + ... + 1755258.

It is an arithmetic number, because the mean of its divisors is an integer number (43167594288).

Almost surely, 2^172666917281 is an apocalyptic number.

It is an amenable number.

172666917281 is a deficient number, since it is larger than the sum of its proper divisors (3459871).

172666917281 is an equidigital number, since it uses as much as digits as its factorization.

172666917281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3459870.

The product of its digits is 3048192, while the sum is 56.

The spelling of 172666917281 in words is "one hundred seventy-two billion, six hundred sixty-six million, nine hundred seventeen thousand, two hundred eighty-one".