21535053613 has 2 divisors, whose sum is σ = 21535053614. Its totient is φ = 21535053612.

The previous prime is 21535053583. The next prime is 21535053641. The reversal of 21535053613 is 31635053512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19723955364 + 1811098249 = 140442^2 + 42557^2 .

It is a cyclic number.

It is not a de Polignac number, because 21535053613 - 2²¹ = 21532956461 is a prime.

It is a super-2 number, since 2×21535053613² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21535053013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10767526806 + 10767526807.

It is an arithmetic number, because the mean of its divisors is an integer number (10767526807).

Almost surely, 2^21535053613 is an apocalyptic number.

It is an amenable number.

21535053613 is a deficient number, since it is larger than the sum of its proper divisors (1).

21535053613 is an equidigital number, since it uses as much as digits as its factorization.

21535053613 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40500, while the sum is 34.

The spelling of 21535053613 in words is "twenty-one billion, five hundred thirty-five million, fifty-three thousand, six hundred thirteen".