1665646040 has 32 divisors (see below), whose sum is σ = 3762657360. Its totient is φ = 663600000.

The previous prime is 1665646007. The next prime is 1665646049. The reversal of 1665646040 is 406465661.

It is a junction number, because it is equal to n+sod(n) for n = 1665645985 and 1665646003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665646049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72911 + ... + 92990.

Almost surely, 2^1665646040 is an apocalyptic number.

1665646040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1665646040 is an abundant number, since it is smaller than the sum of its proper divisors (2097011320).

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

1665646040 is a wasteful number, since it uses less digits than its factorization.

1665646040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166163 (or 166159 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 38.

The square root of 1665646040 is about 40812.3270593579. The cubic root of 1665646040 is about 1185.3890347342.

The spelling of 1665646040 in words is "one billion, six hundred sixty-five million, six hundred forty-six thousand, forty".