20605172 has 24 divisors (see below), whose sum is σ = 41309184. Its totient is φ = 8809632.

The previous prime is 20605159. The next prime is 20605183. The reversal of 20605172 is 27150602.

It is a super-2 number, since 2×20605172² = 849146226299168, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 18413 + ... + 19499.

It is an arithmetic number, because the mean of its divisors is an integer number (1721216).

Almost surely, 2^20605172 is an apocalyptic number.

It is an amenable number.

20605172 is an abundant number, since it is smaller than the sum of its proper divisors (20704012).

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

20605172 is a wasteful number, since it uses less digits than its factorization.

20605172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1775 (or 1773 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 20605172 is about 4539.2920152817. The cubic root of 20605172 is about 274.1524184394.

Adding to 20605172 its reverse (27150602), we get a palindrome (47755774).

The spelling of 20605172 in words is "twenty million, six hundred five thousand, one hundred seventy-two".