22428728 has 32 divisors (see below), whose sum is σ = 48568800. Its totient is φ = 9510912.

The previous prime is 22428727. The next prime is 22428733. The reversal of 22428728 is 82782422.

22428728 = 1787² + 1788² + ... + 1793².

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22428727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3368 + ... + 7496.

It is an arithmetic number, because the mean of its divisors is an integer number (1517775).

Almost surely, 2^22428728 is an apocalyptic number.

22428728 is a gapful number since it is divisible by the number (28) 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 22428728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24284400).

22428728 is an abundant number, since it is smaller than the sum of its proper divisors (26140072).

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

22428728 is a wasteful number, since it uses less digits than its factorization.

22428728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4239 (or 4235 counting only the distinct ones).

The product of its digits is 28672, while the sum is 35.

The square root of 22428728 is about 4735.8978029514. The cubic root of 22428728 is about 282.0124066101.

It can be divided in two parts, 224287 and 28, that multiplied together give a square (6280036 = 2506²).

The spelling of 22428728 in words is "twenty-two million, four hundred twenty-eight thousand, seven hundred twenty-eight".