21193077716836 has 9 divisors (see below), whose sum is σ = 37087902117049. Its totient is φ = 10596534254824.

The previous prime is 21193077716747. The next prime is 21193077716861. The reversal of 21193077716836 is 63861777039112.

The square root of 21193077716836 is 4603594.

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., 827208440100 + 20365869276736 = 909510^2 + 4512856^2 .

It is a super-2 number, since 2×21193077716836² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 8056290 + ... + 10358086.

Almost surely, 2^{21193077716836} is an apocalyptic number.

21193077716836 is the 4603594-th square number.

It is an amenable number.

21193077716836 is a deficient number, since it is larger than the sum of its proper divisors (15894824400213).

21193077716836 is an frugal number, since it uses more digits than its factorization.

21193077716836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4603598 (or 2301799 counting only the distinct ones).

The product of its (nonzero) digits is 16003008, while the sum is 61.

The spelling of 21193077716836 in words is "twenty-one trillion, one hundred ninety-three billion, seventy-seven million, seven hundred sixteen thousand, eight hundred thirty-six".