21828748257 has 6 divisors (see below), whose sum is σ = 31530414162. Its totient is φ = 14552498832.

The previous prime is 21828748231. The next prime is 21828748303. The reversal of 21828748257 is 75284782812.

21828748257 is a `hidden beast` number, since 2 + 1 + 82 + 87 + 482 + 5 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21686685696 + 142062561 = 147264^2 + 11919^2 .

It is not a de Polignac number, because 21828748257 - 2¹⁹ = 21828223969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21828748057) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1212708228 + ... + 1212708245.

It is an arithmetic number, because the mean of its divisors is an integer number (5255069027).

Almost surely, 2^21828748257 is an apocalyptic number.

It is an amenable number.

21828748257 is a deficient number, since it is larger than the sum of its proper divisors (9701665905).

21828748257 is a wasteful number, since it uses less digits than its factorization.

21828748257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2425416479 (or 2425416476 counting only the distinct ones).

The product of its digits is 4014080, while the sum is 54.

The spelling of 21828748257 in words is "twenty-one billion, eight hundred twenty-eight million, seven hundred forty-eight thousand, two hundred fifty-seven".