1665734400 has 486 divisors, whose sum is σ = 6573381360. Its totient is φ = 402124800.

The previous prime is 1665734353. The next prime is 1665734407. The reversal of 1665734400 is 44375661.

It is a happy number.

1665734400 is a `hidden beast` number, since 166 + 57 + 3 + 440 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665734407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 6969481 + ... + 6969719.

Almost surely, 2^1665734400 is an apocalyptic number.

1665734400 is a gapful number since it is divisible by the number (10) 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 1665734400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3286690680).

1665734400 is an abundant number, since it is smaller than the sum of its proper divisors (4907646960).

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

1665734400 is a wasteful number, since it uses less digits than its factorization.

1665734400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293 (or 260 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 1665734400 is about 40813.4095610744. The cubic root of 1665734400 is about 1185.4099953946.

The spelling of 1665734400 in words is "one billion, six hundred sixty-five million, seven hundred thirty-four thousand, four hundred".