1665506040 has 64 divisors (see below), whose sum is σ = 5450751360. Its totient is φ = 403758720.

The previous prime is 1665506027. The next prime is 1665506041. The reversal of 1665506040 is 406055661.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 1665505992 and 1665506010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665506041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 629554 + ... + 632193.

It is an arithmetic number, because the mean of its divisors is an integer number (85167990).

Almost surely, 2^1665506040 is an apocalyptic number.

1665506040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1665506040 is an abundant number, since it is smaller than the sum of its proper divisors (3785245320).

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

1665506040 is a wasteful number, since it uses less digits than its factorization.

1665506040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1261772 (or 1261768 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 1665506040 is about 40810.6118552516. The cubic root of 1665506040 is about 1185.3558225729.

It can be divided in two parts, 1665 and 506040, that added together give a palindrome (507705).

The spelling of 1665506040 in words is "one billion, six hundred sixty-five million, five hundred six thousand, forty".