20405386 has 32 divisors (see below), whose sum is σ = 33048000. Its totient is φ = 9432192.

The previous prime is 20405383. The next prime is 20405387. The reversal of 20405386 is 68350402.

It is not an unprimeable number, because it can be changed into a prime (20405383) 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 15 ways as a sum of consecutive naturals, for example, 229230 + ... + 229318.

It is an arithmetic number, because the mean of its divisors is an integer number (1032750).

Almost surely, 2^20405386 is an apocalyptic number.

20405386 is a deficient number, since it is larger than the sum of its proper divisors (12642614).

20405386 is a wasteful number, since it uses less digits than its factorization.

20405386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 20405386 is about 4517.2321171266. The cubic root of 20405386 is about 273.2634863502.

Adding to 20405386 its reverse (68350402), we get a palindrome (88755788).

The spelling of 20405386 in words is "twenty million, four hundred five thousand, three hundred eighty-six".