21002282857 has 2 divisors, whose sum is σ = 21002282858. Its totient is φ = 21002282856.

The previous prime is 21002282801. The next prime is 21002282863. The reversal of 21002282857 is 75828220012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15988085136 + 5014197721 = 126444^2 + 70811^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002282857 - 2¹⁵ = 21002250089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21002282897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501141428 + 10501141429.

It is an arithmetic number, because the mean of its divisors is an integer number (10501141429).

Almost surely, 2^21002282857 is an apocalyptic number.

It is an amenable number.

21002282857 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002282857 is an equidigital number, since it uses as much as digits as its factorization.

21002282857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 35840, while the sum is 37.

The spelling of 21002282857 in words is "twenty-one billion, two million, two hundred eighty-two thousand, eight hundred fifty-seven".