20278836 has 72 divisors (see below), whose sum is σ = 54955264. Its totient is φ = 6531840.

The previous prime is 20278799. The next prime is 20278837. The reversal of 20278836 is 63887202.

It is a happy number.

It is a super-2 number, since 2×20278836² = 822462379029792, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20278836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20278837) 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, 29796 + ... + 30468.

Almost surely, 2^20278836 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 20278836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27477632).

20278836 is an abundant number, since it is smaller than the sum of its proper divisors (34676428).

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

20278836 is a wasteful number, since it uses less digits than its factorization.

20278836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723 (or 709 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 20278836 is about 4503.2028601874. The cubic root of 20278836 is about 272.6974065477.

The spelling of 20278836 in words is "twenty million, two hundred seventy-eight thousand, eight hundred thirty-six".