1666167408 has 140 divisors (see below), whose sum is σ = 4870206888. Its totient is φ = 551940480.

The previous prime is 1666167401. The next prime is 1666167409. The reversal of 1666167408 is 8047616661.

It is a super-2 number, since 2×1666167408² = 5552227662962876928, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666167401) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 2460766 + ... + 2461442.

Almost surely, 2^1666167408 is an apocalyptic number.

1666167408 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666167408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2435103444).

1666167408 is an abundant number, since it is smaller than the sum of its proper divisors (3204039480).

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

1666167408 is an equidigital number, since it uses as much as digits as its factorization.

1666167408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 914 (or 893 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 1666167408 is about 40818.7139434843. The cubic root of 1666167408 is about 1185.5127023530.

The spelling of 1666167408 in words is "one billion, six hundred sixty-six million, one hundred sixty-seven thousand, four hundred eight".