20045631 has 4 divisors (see below), whose sum is σ = 26727512. Its totient is φ = 13363752.

The previous prime is 20045629. The next prime is 20045651. The reversal of 20045631 is 13654002.

It is a happy number.

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

It is not a de Polignac number, because 20045631 - 2¹ = 20045629 is a prime.

It is a super-2 number, since 2×20045631² = 803654644376322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20045598 and 20045607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20045621) 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 3 ways as a sum of consecutive naturals, for example, 3340936 + ... + 3340941.

It is an arithmetic number, because the mean of its divisors is an integer number (6681878).

Almost surely, 2^20045631 is an apocalyptic number.

20045631 is a deficient number, since it is larger than the sum of its proper divisors (6681881).

20045631 is an equidigital number, since it uses as much as digits as its factorization.

20045631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6681880.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 20045631 is about 4477.2347492621. The cubic root of 20045631 is about 271.6480408440.

Adding to 20045631 its reverse (13654002), we get a palindrome (33699633).

The spelling of 20045631 in words is "twenty million, forty-five thousand, six hundred thirty-one".