20288778 has 8 divisors (see below), whose sum is σ = 40577568. Its totient is φ = 6762924.

The previous prime is 20288767. The next prime is 20288797. The reversal of 20288778 is 87788202.

It is a sphenic number, since it is the product of 3 distinct primes.

20288778 is an admirable number.

It is a Curzon number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1690726 + ... + 1690737.

It is an arithmetic number, because the mean of its divisors is an integer number (5072196).

Almost surely, 2^20288778 is an apocalyptic number.

20288778 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20288778 is a wasteful number, since it uses less digits than its factorization.

20288778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3381468.

The product of its (nonzero) digits is 100352, while the sum is 42.

The square root of 20288778 is about 4504.3066059051. The cubic root of 20288778 is about 272.7419639157.

The spelling of 20288778 in words is "twenty million, two hundred eighty-eight thousand, seven hundred seventy-eight".