1665223572 has 12 divisors (see below), whose sum is σ = 3885521696. Its totient is φ = 555074520.

The previous prime is 1665223543. The next prime is 1665223579. The reversal of 1665223572 is 2753225661.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 1665223572.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665223579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69384304 + ... + 69384327.

Almost surely, 2^1665223572 is an apocalyptic number.

1665223572 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1665223572 is an abundant number, since it is smaller than the sum of its proper divisors (2220298124).

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

1665223572 is a wasteful number, since it uses less digits than its factorization.

1665223572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138768638 (or 138768636 counting only the distinct ones).

The product of its digits is 151200, while the sum is 39.

The square root of 1665223572 is about 40807.1509909722. The cubic root of 1665223572 is about 1185.2888071012.

The spelling of 1665223572 in words is "one billion, six hundred sixty-five million, two hundred twenty-three thousand, five hundred seventy-two".