20689807446025 has 81 divisors (see below), whose sum is σ = 27753621362229. Its totient is φ = 15297286114560.

The previous prime is 20689807445969. The next prime is 20689807446029. The reversal of 20689807446025 is 52064470898602.

The square root of 20689807446025 is 4548605.

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

It can be written as a sum of positive squares in 4 ways, for example, as 483955357561 + 20205852088464 = 695669^2 + 4495092^2 .

It is not a de Polignac number, because 20689807446025 - 2⁷ = 20689807445897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20689807446029) by changing a digit.

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 80 ways as a sum of consecutive naturals, for example, 22811253622 + ... + 22811254528.

Almost surely, 2^{20689807446025} is an apocalyptic number.

20689807446025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20689807446025 is the 4548605-th square number.

20689807446025 is the 2274303-rd centered octagonal number.

It is an amenable number.

20689807446025 is a deficient number, since it is larger than the sum of its proper divisors (7063813916204).

20689807446025 is an frugal number, since it uses more digits than its factorization.

20689807446025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1976 (or 988 counting only the distinct ones).

The product of its (nonzero) digits is 46448640, while the sum is 61.

The spelling of 20689807446025 in words is "twenty trillion, six hundred eighty-nine billion, eight hundred seven million, four hundred forty-six thousand, twenty-five".