21428275456 has 81 divisors (see below), whose sum is σ = 49794266739. Its totient is φ = 9176520192.

The previous prime is 21428275439. The next prime is 21428275471. The reversal of 21428275456 is 65457282412.

The square root of 21428275456 is 146384.

It is a perfect power (a square), and thus also a powerful number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 16394355 + ... + 16395661.

Almost surely, 2^21428275456 is an apocalyptic number.

21428275456 is the 146384-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21428275456

21428275456 is an abundant number, since it is smaller than the sum of its proper divisors (28365991283).

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

21428275456 is an frugal number, since it uses more digits than its factorization.

21428275456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2644 (or 1316 counting only the distinct ones).

The product of its digits is 1075200, while the sum is 46.

The spelling of 21428275456 in words is "twenty-one billion, four hundred twenty-eight million, two hundred seventy-five thousand, four hundred fifty-six".