191807209764 has 135 divisors (see below), whose sum is σ = 519928265857. Its totient is φ = 61657479072.

The previous prime is 191807209753. The next prime is 191807209771. The reversal of 191807209764 is 467902708191.

The square root of 191807209764 is 437958.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 100579048164 + 91228161600 = 317142^2 + 302040^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 191807209764.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 228613657 + ... + 228614495.

Almost surely, 2^191807209764 is an apocalyptic number.

191807209764 is the 437958-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191807209764

191807209764 is an abundant number, since it is smaller than the sum of its proper divisors (328121056093).

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

191807209764 is an frugal number, since it uses more digits than its factorization.

191807209764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1752 (or 873 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 54.

The spelling of 191807209764 in words is "one hundred ninety-one billion, eight hundred seven million, two hundred nine thousand, seven hundred sixty-four".