20306631 has 16 divisors (see below), whose sum is σ = 28454400. Its totient is φ = 12856800.

The previous prime is 20306623. The next prime is 20306633. The reversal of 20306631 is 13660302.

It is not a de Polignac number, because 20306631 - 2³ = 20306623 is a prime.

It is a super-3 number, since 3×20306631³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 20306598 and 20306607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20306633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9445 + ... + 11393.

It is an arithmetic number, because the mean of its divisors is an integer number (1778400).

Almost surely, 2^20306631 is an apocalyptic number.

20306631 is a deficient number, since it is larger than the sum of its proper divisors (8147769).

20306631 is a wasteful number, since it uses less digits than its factorization.

20306631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2126.

The product of its (nonzero) digits is 648, while the sum is 21.

The square root of 20306631 is about 4506.2879402009. The cubic root of 20306631 is about 272.8219397321.

Adding to 20306631 its reverse (13660302), we get a palindrome (33966933).

The spelling of 20306631 in words is "twenty million, three hundred six thousand, six hundred thirty-one".