20686168722025 has 27 divisors (see below), whose sum is σ = 25743362905911. Its totient is φ = 16489462649040.

The previous prime is 20686168722019. The next prime is 20686168722049. The reversal of 20686168722025 is 52022786168602.

The square root of 20686168722025 is 4548205.

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., 7447020739929 + 13239147982096 = 2728923^2 + 3638564^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20686168722025 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 6981493194 + ... + 6981496156.

Almost surely, 2^{20686168722025} is an apocalyptic number.

20686168722025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20686168722025 is the 4548205-th square number.

20686168722025 is the 2274103-rd centered octagonal number.

It is an amenable number.

20686168722025 is a deficient number, since it is larger than the sum of its proper divisors (5057194183886).

20686168722025 is an frugal number, since it uses more digits than its factorization.

20686168722025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6550 (or 3275 counting only the distinct ones).

The product of its (nonzero) digits is 7741440, while the sum is 55.

The spelling of 20686168722025 in words is "twenty trillion, six hundred eighty-six billion, one hundred sixty-eight million, seven hundred twenty-two thousand, twenty-five".