20405996 has 12 divisors (see below), whose sum is σ = 38457552. Its totient is φ = 9418128.

The previous prime is 20405993. The next prime is 20406011. The reversal of 20405996 is 69950402.

It is not an unprimeable number, because it can be changed into a prime (20405993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196160 + ... + 196263.

It is an arithmetic number, because the mean of its divisors is an integer number (3204796).

Almost surely, 2^20405996 is an apocalyptic number.

20405996 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

20405996 is a deficient number, since it is larger than the sum of its proper divisors (18051556).

20405996 is a wasteful number, since it uses less digits than its factorization.

20405996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392440 (or 392438 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 20405996 is about 4517.2996358444. The cubic root of 20405996 is about 273.2662093088.

The spelling of 20405996 in words is "twenty million, four hundred five thousand, nine hundred ninety-six".