20404992 has 54 divisors (see below), whose sum is σ = 54642252. Its totient is φ = 6759936.

The previous prime is 20404991. The next prime is 20404997. The reversal of 20404992 is 29940402.

It is not an unprimeable number, because it can be changed into a prime (20404991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 125103 + ... + 125265.

Almost surely, 2^20404992 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 20404992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27321126).

20404992 is an abundant number, since it is smaller than the sum of its proper divisors (34237260).

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

20404992 is an frugal number, since it uses more digits than its factorization.

20404992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 20404992 is about 4517.1885061396. The cubic root of 20404992 is about 273.2617275579.

The spelling of 20404992 in words is "twenty million, four hundred four thousand, nine hundred ninety-two".