166706770438640 has 20 divisors (see below), whose sum is σ = 387593241270024. Its totient is φ = 66682708175424.

The previous prime is 166706770438639. The next prime is 166706770438673. The reversal of 166706770438640 is 46834077607661.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×166706770438640² (a number of 29 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (65) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1041917315162 + ... + 1041917315321.

Almost surely, 2^{166706770438640} is an apocalyptic number.

166706770438640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166706770438640 is an abundant number, since it is smaller than the sum of its proper divisors (220886470831384).

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

166706770438640 is a wasteful number, since it uses less digits than its factorization.

166706770438640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2083834630496 (or 2083834630490 counting only the distinct ones).

The product of its (nonzero) digits is 170698752, while the sum is 65.

The spelling of 166706770438640 in words is "one hundred sixty-six trillion, seven hundred six billion, seven hundred seventy million, four hundred thirty-eight thousand, six hundred forty".