21728249740 has 12 divisors (see below), whose sum is σ = 45629324496. Its totient is φ = 8691299888.

The previous prime is 21728249717. The next prime is 21728249747. The reversal of 21728249740 is 4794282712.

It is not an unprimeable number, because it can be changed into a prime (21728249747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 543206224 + ... + 543206263.

It is an arithmetic number, because the mean of its divisors is an integer number (3802443708).

Almost surely, 2^21728249740 is an apocalyptic number.

21728249740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21728249740 is an abundant number, since it is smaller than the sum of its proper divisors (23901074756).

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

21728249740 is a wasteful number, since it uses less digits than its factorization.

21728249740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1086412496 (or 1086412494 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 46.

The spelling of 21728249740 in words is "twenty-one billion, seven hundred twenty-eight million, two hundred forty-nine thousand, seven hundred forty".