20505071725 has 6 divisors (see below), whose sum is σ = 25426288970. Its totient is φ = 16404057360.

The previous prime is 20505071669. The next prime is 20505071729. The reversal of 20505071725 is 52717050502.

It can be written as a sum of positive squares in 3 ways, for example, as 1910476681 + 18594595044 = 43709^2 + 136362^2 .

It is not a de Polignac number, because 20505071725 - 2¹³ = 20505063533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20505071729) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 410101410 + ... + 410101459.

Almost surely, 2^20505071725 is an apocalyptic number.

20505071725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20505071725 is a deficient number, since it is larger than the sum of its proper divisors (4921217245).

20505071725 is an equidigital number, since it uses as much as digits as its factorization.

20505071725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820202879 (or 820202874 counting only the distinct ones).

The product of its (nonzero) digits is 24500, while the sum is 34.

The spelling of 20505071725 in words is "twenty billion, five hundred five million, seventy-one thousand, seven hundred twenty-five".