21075775178896 has 15 divisors (see below), whose sum is σ = 40834349988121. Its totient is φ = 10537878407776.

The previous prime is 21075775178851. The next prime is 21075775178917. The reversal of 21075775178896 is 69887157757012.

The square root of 21075775178896 is 4590836.

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., 20869949636496 + 205825542400 = 4568364^2 + 453680^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 17789490 + ... + 18937198.

Almost surely, 2^{21075775178896} is an apocalyptic number.

21075775178896 is the 4590836-th square number.

It is an amenable number.

21075775178896 is a deficient number, since it is larger than the sum of its proper divisors (19758574809225).

21075775178896 is an frugal number, since it uses more digits than its factorization.

21075775178896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2295426 (or 1147711 counting only the distinct ones).

The product of its (nonzero) digits is 414892800, while the sum is 73.

The spelling of 21075775178896 in words is "twenty-one trillion, seventy-five billion, seven hundred seventy-five million, one hundred seventy-eight thousand, eight hundred ninety-six".