20019118878529 has 3 divisors (see below), whose sum is σ = 20019123352803. Its totient is φ = 20019114404256.

The previous prime is 20019118878469. The next prime is 20019118878641. The reversal of 20019118878529 is 92587881191002.

The square root of 20019118878529 is 4474273.

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., 12829470330625 + 7189648547904 = 3581825^2 + 2681352^2 .

It is not a de Polignac number, because 20019118878529 - 2¹³ = 20019118870337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20019112878529) 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, 2237137 + ... + 6711409.

It is an arithmetic number, because the mean of its divisors is an integer number (6673041117601).

Almost surely, 2^{20019118878529} is an apocalyptic number.

20019118878529 is the 4474273-rd square number.

20019118878529 is the 2237137-th centered octagonal number.

It is an amenable number.

20019118878529 is a deficient number, since it is larger than the sum of its proper divisors (4474274).

20019118878529 is an frugal number, since it uses more digits than its factorization.

20019118878529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8948546 (or 4474273 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 61.

The spelling of 20019118878529 in words is "twenty trillion, nineteen billion, one hundred eighteen million, eight hundred seventy-eight thousand, five hundred twenty-nine".