1665137540 has 48 divisors (see below), whose sum is σ = 3827101824. Its totient is φ = 603532800.

The previous prime is 1665137483. The next prime is 1665137543. The reversal of 1665137540 is 457315661.

It is a junction number, because it is equal to n+sod(n) for n = 1665137494 and 1665137503.

It is not an unprimeable number, because it can be changed into a prime (1665137543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56252 + ... + 80588.

It is an arithmetic number, because the mean of its divisors is an integer number (79731288).

Almost surely, 2^1665137540 is an apocalyptic number.

1665137540 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 1665137540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1913550912).

1665137540 is an abundant number, since it is smaller than the sum of its proper divisors (2161964284).

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

1665137540 is a wasteful number, since it uses less digits than its factorization.

1665137540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24668 (or 24666 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 38.

The square root of 1665137540 is about 40806.0968483877. The cubic root of 1665137540 is about 1185.2683945223.

The spelling of 1665137540 in words is "one billion, six hundred sixty-five million, one hundred thirty-seven thousand, five hundred forty".