20591172 has 90 divisors (see below), whose sum is σ = 62666142. Its totient is φ = 5878656.

The previous prime is 20591171. The next prime is 20591191. The reversal of 20591172 is 27119502.

20591172 is a `hidden beast` number, since 2 + 0 + 591 + 1 + 72 = 666.

20591172 is nontrivially palindromic in base 13.

It can be written as a sum of positive squares in only one way, i.e., 20575296 + 15876 = 4536^2 + 126^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20591171) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 15228 + ... + 16524.

Almost surely, 2^20591172 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 20591172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31333071).

20591172 is an abundant number, since it is smaller than the sum of its proper divisors (42074970).

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

20591172 is a wasteful number, since it uses less digits than its factorization.

20591172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1327 (or 1309 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 20591172 is about 4537.7496625530. The cubic root of 20591172 is about 274.0903142349.

The spelling of 20591172 in words is "twenty million, five hundred ninety-one thousand, one hundred seventy-two".