166706770438639 has 2 divisors, whose sum is σ = 166706770438640. Its totient is φ = 166706770438638.

The previous prime is 166706770438633. The next prime is 166706770438673. The reversal of 166706770438639 is 936834077607661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 166706770438639 - 2³ = 166706770438631 is a prime.

It is a super-3 number, since 3×166706770438639³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166706770438631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83353385219319 + 83353385219320.

It is an arithmetic number, because the mean of its divisors is an integer number (83353385219320).

Almost surely, 2^{166706770438639} is an apocalyptic number.

166706770438639 is a deficient number, since it is larger than the sum of its proper divisors (1).

166706770438639 is an equidigital number, since it uses as much as digits as its factorization.

166706770438639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152216576, while the sum is 73.

The spelling of 166706770438639 in words is "one hundred sixty-six trillion, seven hundred six billion, seven hundred seventy million, four hundred thirty-eight thousand, six hundred thirty-nine".