20906906 has 8 divisors (see below), whose sum is σ = 33205140. Its totient is φ = 9838528.

The previous prime is 20906903. The next prime is 20906917. The reversal of 20906906 is 60960902.

It can be written as a sum of positive squares in 2 ways, for example, as 20620681 + 286225 = 4541^2 + 535^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (20906903) 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, 307421 + ... + 307488.

Almost surely, 2^20906906 is an apocalyptic number.

20906906 is a deficient number, since it is larger than the sum of its proper divisors (12298234).

20906906 is a wasteful number, since it uses less digits than its factorization.

20906906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 614928.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 20906906 is about 4572.4070247518. The cubic root of 20906906 is about 275.4841323180.

It can be divided in two parts, 20906 and 906, that added together give a palindrome (21812).

The spelling of 20906906 in words is "twenty million, nine hundred six thousand, nine hundred six".