1665405126 has 192 divisors, whose sum is σ = 4709892096. Its totient is φ = 412689600.

The previous prime is 1665405121. The next prime is 1665405139. The reversal of 1665405126 is 6215045661.

1665405126 is a `hidden beast` number, since 1 + 66 + 540 + 51 + 2 + 6 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665405121) 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 95 ways as a sum of consecutive naturals, for example, 3565945 + ... + 3566411.

It is an arithmetic number, because the mean of its divisors is an integer number (24530688).

Almost surely, 2^1665405126 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1665405126, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2354946048).

1665405126 is an abundant number, since it is smaller than the sum of its proper divisors (3044486970).

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

1665405126 is a wasteful number, since it uses less digits than its factorization.

1665405126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 607 (or 604 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 1665405126 is about 40809.3754669194. The cubic root of 1665405126 is about 1185.3318816183.

The spelling of 1665405126 in words is "one billion, six hundred sixty-five million, four hundred five thousand, one hundred twenty-six".