20656438 has 16 divisors (see below), whose sum is σ = 35271936. Its totient is φ = 8980840.

The previous prime is 20656429. The next prime is 20656451. The reversal of 20656438 is 83465602.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 19906 + ... + 20917.

It is an arithmetic number, because the mean of its divisors is an integer number (2204496).

Almost surely, 2^20656438 is an apocalyptic number.

20656438 is a deficient number, since it is larger than the sum of its proper divisors (14615498).

20656438 is a wasteful number, since it uses less digits than its factorization.

20656438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40859.

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 20656438 is about 4544.9354230836. The cubic root of 20656438 is about 274.3795953485.

It can be divided in two parts, 206564 and 38, that added together give a palindrome (206602).

The spelling of 20656438 in words is "twenty million, six hundred fifty-six thousand, four hundred thirty-eight".