20406738 has 16 divisors (see below), whose sum is σ = 44523936. Its totient is φ = 6183840.

The previous prime is 20406697. The next prime is 20406767. The reversal of 20406738 is 83760402.

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, 154531 + ... + 154662.

It is an arithmetic number, because the mean of its divisors is an integer number (2782746).

Almost surely, 2^20406738 is an apocalyptic number.

20406738 is an abundant number, since it is smaller than the sum of its proper divisors (24117198).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20406738 is a wasteful number, since it uses less digits than its factorization.

20406738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309209.

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 20406738 is about 4517.3817638097. The cubic root of 20406738 is about 273.2695214247.

It can be divided in two parts, 2040 and 6738, that added together give a palindrome (8778).

The spelling of 20406738 in words is "twenty million, four hundred six thousand, seven hundred thirty-eight".