20405388 has 24 divisors (see below), whose sum is σ = 47844160. Its totient is φ = 6768720.

The previous prime is 20405387. The next prime is 20405443. The reversal of 20405388 is 88350402.

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 7 ways as a sum of consecutive naturals, for example, 1498 + ... + 6561.

Almost surely, 2^20405388 is an apocalyptic number.

It is an amenable number.

20405388 is an abundant number, since it is smaller than the sum of its proper divisors (27438772).

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

20405388 is a wasteful number, since it uses less digits than its factorization.

20405388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8277 (or 8275 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 20405388 is about 4517.2323385011. The cubic root of 20405388 is about 273.2634952780.

The spelling of 20405388 in words is "twenty million, four hundred five thousand, three hundred eighty-eight".