20725005 has 16 divisors (see below), whose sum is σ = 37897344. Its totient is φ = 9474240.

The previous prime is 20724973. The next prime is 20725007. The reversal of 20725005 is 50052702.

It is not a de Polignac number, because 20725005 - 2⁵ = 20724973 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20725007) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 98586 + ... + 98795.

It is an arithmetic number, because the mean of its divisors is an integer number (2368584).

Almost surely, 2^20725005 is an apocalyptic number.

It is an amenable number.

20725005 is a deficient number, since it is larger than the sum of its proper divisors (17172339).

20725005 is a wasteful number, since it uses less digits than its factorization.

20725005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197396.

The product of its (nonzero) digits is 700, while the sum is 21.

The square root of 20725005 is about 4552.4724051882. The cubic root of 20725005 is about 274.6828520157.

Adding to 20725005 its reverse (50052702), we get a palindrome (70777707).

The spelling of 20725005 in words is "twenty million, seven hundred twenty-five thousand, five".