20725313221 has 16 divisors (see below), whose sum is σ = 22742899200. Its totient is φ = 18812952000.

The previous prime is 20725313209. The next prime is 20725313239. The reversal of 20725313221 is 12231352702.

It is a cyclic number.

It is not a de Polignac number, because 20725313221 - 2⁹ = 20725312709 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20725313221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20725313281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 114706 + ... + 233683.

It is an arithmetic number, because the mean of its divisors is an integer number (1421431200).

Almost surely, 2^20725313221 is an apocalyptic number.

It is an amenable number.

20725313221 is a deficient number, since it is larger than the sum of its proper divisors (2017585979).

20725313221 is a wasteful number, since it uses less digits than its factorization.

20725313221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348540.

The product of its (nonzero) digits is 5040, while the sum is 28.

Adding to 20725313221 its reverse (12231352702), we get a palindrome (32956665923).

The spelling of 20725313221 in words is "twenty billion, seven hundred twenty-five million, three hundred thirteen thousand, two hundred twenty-one".