178720099009 has 3 divisors (see below), whose sum is σ = 178720521763. Its totient is φ = 178719676256.

The previous prime is 178720098979. The next prime is 178720099027. The reversal of 178720099009 is 900990027871.

The square root of 178720099009 is 422753.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 6933060225 + 171787038784 = 83265^2 + 414472^2 .

It is a de Polignac number, because none of the positive numbers 2^k-178720099009 is a prime.

It is a super-3 number, since 3×178720099009³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (178720099049) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 211377 + ... + 634129.

Almost surely, 2^178720099009 is an apocalyptic number.

178720099009 is the 422753-rd square number.

178720099009 is the 211377-th centered octagonal number.

It is an amenable number.

178720099009 is a deficient number, since it is larger than the sum of its proper divisors (422754).

178720099009 is an frugal number, since it uses more digits than its factorization.

178720099009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845506 (or 422753 counting only the distinct ones).

The product of its (nonzero) digits is 571536, while the sum is 52.

The spelling of 178720099009 in words is "one hundred seventy-eight billion, seven hundred twenty million, ninety-nine thousand, nine".