1664613216 has 72 divisors (see below), whose sum is σ = 5409999504. Its totient is φ = 475603200.

The previous prime is 1664613193. The next prime is 1664613221. The reversal of 1664613216 is 6123164661.

It is a happy number.

1664613216 is a `hidden beast` number, since 1 + 6 + 646 + 1 + 3 + 2 + 1 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 410835 + ... + 414866.

It is an arithmetic number, because the mean of its divisors is an integer number (75138882).

Almost surely, 2^1664613216 is an apocalyptic number.

1664613216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1664613216 is an abundant number, since it is smaller than the sum of its proper divisors (3745386288).

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

1664613216 is a wasteful number, since it uses less digits than its factorization.

1664613216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825724 (or 825713 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 1664613216 is about 40799.6717633855. The cubic root of 1664613216 is about 1185.1439743884.

Adding to 1664613216 its reverse (6123164661), we get a palindrome (7787777877).

The spelling of 1664613216 in words is "one billion, six hundred sixty-four million, six hundred thirteen thousand, two hundred sixteen".