20725345 has 4 divisors (see below), whose sum is σ = 24870420. Its totient is φ = 16580272.

The previous prime is 20725339. The next prime is 20725361. The reversal of 20725345 is 54352702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54352702 = 2 ⋅27176351.

It can be written as a sum of positive squares in 2 ways, for example, as 16064064 + 4661281 = 4008^2 + 2159^2 .

It is a cyclic number.

It is not a de Polignac number, because 20725345 - 2³ = 20725337 is a prime.

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 3 ways as a sum of consecutive naturals, for example, 2072530 + ... + 2072539.

It is an arithmetic number, because the mean of its divisors is an integer number (6217605).

Almost surely, 2^20725345 is an apocalyptic number.

It is an amenable number.

20725345 is a deficient number, since it is larger than the sum of its proper divisors (4145075).

20725345 is an equidigital number, since it uses as much as digits as its factorization.

20725345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4145074.

The product of its (nonzero) digits is 8400, while the sum is 28.

The square root of 20725345 is about 4552.5097473811. The cubic root of 20725345 is about 274.6843540926.

It can be divided in two parts, 207 and 25345, that added together give a palindrome (25552).

The spelling of 20725345 in words is "twenty million, seven hundred twenty-five thousand, three hundred forty-five".