509169991680 has 1536 divisors, whose sum is σ = 2205436248000. Its totient is φ = 112368549888.

The previous prime is 509169991657. The next prime is 509169991769. The reversal of 509169991680 is 86199961905.

It is a happy number.

509169991680 is a `hidden beast` number, since 509 + 1 + 69 + 9 + 9 + 1 + 68 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1536).

It is a super-2 number, since 2×509169991680² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 17557585906 + ... + 17557585934.

Almost surely, 2^509169991680 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 509169991680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1102718124000).

509169991680 is an abundant number, since it is smaller than the sum of its proper divisors (1696266256320).

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

509169991680 is an frugal number, since it uses more digits than its factorization.

509169991680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99 (or 46 counting only the distinct ones).

The product of its (nonzero) digits is 9447840, while the sum is 63.

The spelling of 509169991680 in words is "five hundred nine billion, one hundred sixty-nine million, nine hundred ninety-one thousand, six hundred eighty".