20403936 has 144 divisors (see below), whose sum is σ = 68796000. Its totient is φ = 5612544.

The previous prime is 20403931. The next prime is 20403941. The reversal of 20403936 is 63930402.

It is an interprime number because it is at equal distance from previous prime (20403931) and next prime (20403941).

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20403931) 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 23 ways as a sum of consecutive naturals, for example, 58290 + ... + 58638.

It is an arithmetic number, because the mean of its divisors is an integer number (477750).

Almost surely, 2^20403936 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20403936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34398000).

20403936 is an abundant number, since it is smaller than the sum of its proper divisors (48392064).

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

20403936 is a wasteful number, since it uses less digits than its factorization.

20403936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 20403936 is about 4517.0716177630. The cubic root of 20403936 is about 273.2570135258.

The spelling of 20403936 in words is "twenty million, four hundred three thousand, nine hundred thirty-six".