22281738728 has 8 divisors (see below), whose sum is σ = 41778260130. Its totient is φ = 11140869360.

The previous prime is 22281738719. The next prime is 22281738733. The reversal of 22281738728 is 82783718222.

It can be written as a sum of positive squares in only one way, i.e., 14051257444 + 8230481284 = 118538^2 + 90722^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1392608663 + ... + 1392608678.

Almost surely, 2^22281738728 is an apocalyptic number.

It is an amenable number.

22281738728 is a deficient number, since it is larger than the sum of its proper divisors (19496521402).

22281738728 is a wasteful number, since it uses less digits than its factorization.

22281738728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2785217347 (or 2785217343 counting only the distinct ones).

The product of its digits is 1204224, while the sum is 50.

The spelling of 22281738728 in words is "twenty-two billion, two hundred eighty-one million, seven hundred thirty-eight thousand, seven hundred twenty-eight".