20730725 has 6 divisors (see below), whose sum is σ = 25706130. Its totient is φ = 16584560.

The previous prime is 20730719. The next prime is 20730733. The reversal of 20730725 is 52703702.

It can be written as a sum of positive squares in 3 ways, for example, as 4866436 + 15864289 = 2206^2 + 3983^2 .

It is not a de Polignac number, because 20730725 - 2¹⁰ = 20729701 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20730694 and 20730703.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 414590 + ... + 414639.

It is an arithmetic number, because the mean of its divisors is an integer number (4284355).

Almost surely, 2^20730725 is an apocalyptic number.

20730725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20730725 is a deficient number, since it is larger than the sum of its proper divisors (4975405).

20730725 is an equidigital number, since it uses as much as digits as its factorization.

20730725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 829239 (or 829234 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 26.

The square root of 20730725 is about 4553.1005919044. The cubic root of 20730725 is about 274.7081200657.

The spelling of 20730725 in words is "twenty million, seven hundred thirty thousand, seven hundred twenty-five".