20655172272 has 120 divisors (see below), whose sum is σ = 62117118000. Its totient is φ = 5897084928.

The previous prime is 20655172267. The next prime is 20655172277. The reversal of 20655172272 is 27227155602.

It is an interprime number because it is at equal distance from previous prime (20655172267) and next prime (20655172277).

It is a super-2 number, since 2×20655172272² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20655172272.

It is not an unprimeable number, because it can be changed into a prime (20655172277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4440604 + ... + 4445252.

It is an arithmetic number, because the mean of its divisors is an integer number (517642650).

Almost surely, 2^20655172272 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20655172272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31058559000).

20655172272 is an abundant number, since it is smaller than the sum of its proper divisors (41461945728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20655172272 is a wasteful number, since it uses less digits than its factorization.

20655172272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6563 (or 6550 counting only the distinct ones).

The product of its (nonzero) digits is 117600, while the sum is 39.

The spelling of 20655172272 in words is "twenty billion, six hundred fifty-five million, one hundred seventy-two thousand, two hundred seventy-two".