1665493590 has 16 divisors (see below), whose sum is σ = 3997184688. Its totient is φ = 444131616.

The previous prime is 1665493573. The next prime is 1665493603. The reversal of 1665493590 is 953945661.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27758197 + ... + 27758256.

It is an arithmetic number, because the mean of its divisors is an integer number (249824043).

Almost surely, 2^1665493590 is an apocalyptic number.

1665493590 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1665493590 is an abundant number, since it is smaller than the sum of its proper divisors (2331691098).

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

1665493590 is a wasteful number, since it uses less digits than its factorization.

1665493590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55516463.

The product of its (nonzero) digits is 874800, while the sum is 48.

The square root of 1665493590 is about 40810.4593211103. The cubic root of 1665493590 is about 1185.3528689728.

The spelling of 1665493590 in words is "one billion, six hundred sixty-five million, four hundred ninety-three thousand, five hundred ninety".