20470531 has 4 divisors (see below), whose sum is σ = 20483064. Its totient is φ = 20458000.

The previous prime is 20470519. The next prime is 20470547. The reversal of 20470531 is 13507402.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20470531 - 2⁹ = 20470019 is a prime.

It is a super-2 number, since 2×20470531² = 838085278843922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20470501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3370 + ... + 7231.

It is an arithmetic number, because the mean of its divisors is an integer number (5120766).

Almost surely, 2^20470531 is an apocalyptic number.

20470531 is a deficient number, since it is larger than the sum of its proper divisors (12533).

20470531 is a wasteful number, since it uses less digits than its factorization.

20470531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12532.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 20470531 is about 4524.4370920591. The cubic root of 20470531 is about 273.5539789206.

Adding to 20470531 its reverse (13507402), we get a palindrome (33977933).

The spelling of 20470531 in words is "twenty million, four hundred seventy thousand, five hundred thirty-one".