20400788 has 12 divisors (see below), whose sum is σ = 36055572. Its totient is φ = 10099200.

The previous prime is 20400719. The next prime is 20400803. The reversal of 20400788 is 88700402.

It can be written as a sum of positive squares in 2 ways, for example, as 11710084 + 8690704 = 3422^2 + 2948^2 .

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 20400788.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24845 + ... + 25652.

It is an arithmetic number, because the mean of its divisors is an integer number (3004631).

Almost surely, 2^20400788 is an apocalyptic number.

It is an amenable number.

20400788 is a deficient number, since it is larger than the sum of its proper divisors (15654784).

20400788 is a wasteful number, since it uses less digits than its factorization.

20400788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50602 (or 50600 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 29.

The square root of 20400788 is about 4516.7231484783. The cubic root of 20400788 is about 273.2429597452.

The spelling of 20400788 in words is "twenty million, four hundred thousand, seven hundred eighty-eight".