20172481 has 4 divisors (see below), whose sum is σ = 23054272. Its totient is φ = 17290692.

The previous prime is 20172469. The next prime is 20172491. The reversal of 20172481 is 18427102.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20172481 - 2¹¹ = 20170433 is a prime.

It is a super-2 number, since 2×20172481² = 813857979390722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20172401) 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 3 ways as a sum of consecutive naturals, for example, 1440885 + ... + 1440898.

It is an arithmetic number, because the mean of its divisors is an integer number (5763568).

Almost surely, 2^20172481 is an apocalyptic number.

It is an amenable number.

20172481 is a deficient number, since it is larger than the sum of its proper divisors (2881791).

20172481 is an equidigital number, since it uses as much as digits as its factorization.

20172481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2881790.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 20172481 is about 4491.3785188960. The cubic root of 20172481 is about 272.2198383119.

Adding to 20172481 its reverse (18427102), we get a palindrome (38599583).

The spelling of 20172481 in words is "twenty million, one hundred seventy-two thousand, four hundred eighty-one".