21272535857 has 2 divisors, whose sum is σ = 21272535858. Its totient is φ = 21272535856.

The previous prime is 21272535847. The next prime is 21272535881. The reversal of 21272535857 is 75853527212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20545208896 + 727326961 = 143336^2 + 26969^2 .

It is a cyclic number.

It is not a de Polignac number, because 21272535857 - 2¹⁸ = 21272273713 is a prime.

It is not a weakly prime, because it can be changed into another prime (21272535847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10636267928 + 10636267929.

It is an arithmetic number, because the mean of its divisors is an integer number (10636267929).

Almost surely, 2^21272535857 is an apocalyptic number.

It is an amenable number.

21272535857 is a deficient number, since it is larger than the sum of its proper divisors (1).

21272535857 is an equidigital number, since it uses as much as digits as its factorization.

21272535857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1176000, while the sum is 47.

The spelling of 21272535857 in words is "twenty-one billion, two hundred seventy-two million, five hundred thirty-five thousand, eight hundred fifty-seven".