21228678000 has 480 divisors, whose sum is σ = 79086938112. Its totient is φ = 5294784000.

The previous prime is 21228677957. The next prime is 21228678007. The reversal of 21228678000 is 87682212.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21228678007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 19457455 + ... + 19458545.

Almost surely, 2^21228678000 is an apocalyptic number.

21228678000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21228678000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39543469056).

21228678000 is an abundant number, since it is smaller than the sum of its proper divisors (57858260112).

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

21228678000 is a wasteful number, since it uses less digits than its factorization.

21228678000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1190 (or 1171 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The spelling of 21228678000 in words is "twenty-one billion, two hundred twenty-eight million, six hundred seventy-eight thousand".