20725705 has 64 divisors (see below), whose sum is σ = 34546176. Its totient is φ = 11520000.

The previous prime is 20725693. The next prime is 20725709. The reversal of 20725705 is 50752702.

It is not a de Polignac number, because 20725705 - 2⁵ = 20725673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20725709) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 205155 + ... + 205255.

It is an arithmetic number, because the mean of its divisors is an integer number (539784).

Almost surely, 2^20725705 is an apocalyptic number.

It is an amenable number.

20725705 is a deficient number, since it is larger than the sum of its proper divisors (13820471).

20725705 is a wasteful number, since it uses less digits than its factorization.

20725705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178.

The product of its (nonzero) digits is 4900, while the sum is 28.

The square root of 20725705 is about 4552.5492858397. The cubic root of 20725705 is about 274.6859445092.

It can be divided in two parts, 2072 and 5705, that added together give a palindrome (7777).

The spelling of 20725705 in words is "twenty million, seven hundred twenty-five thousand, seven hundred five".