1666406800 has 30 divisors (see below), whose sum is σ = 4003543298. Its totient is φ = 666562560.

The previous prime is 1666406771. The next prime is 1666406881. The reversal of 1666406800 is 86046661.

It can be written as a sum of positive squares in 3 ways, for example, as 364351744 + 1302055056 = 19088^2 + 36084^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1666406800.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2082609 + ... + 2083408.

Almost surely, 2^1666406800 is an apocalyptic number.

1666406800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666406800 is an abundant number, since it is smaller than the sum of its proper divisors (2337136498).

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

1666406800 is a wasteful number, since it uses less digits than its factorization.

1666406800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4166035 (or 4166024 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 1666406800 is about 40821.6462186424. The cubic root of 1666406800 is about 1185.5694770933.

The spelling of 1666406800 in words is "one billion, six hundred sixty-six million, four hundred six thousand, eight hundred".