21335155643 has 2 divisors, whose sum is σ = 21335155644. Its totient is φ = 21335155642.

The previous prime is 21335155549. The next prime is 21335155661. The reversal of 21335155643 is 34655153312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21335155643 - 2²⁸ = 21066720187 is a prime.

It is a super-2 number, since 2×21335155643² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21335155597 and 21335155606.

It is not a weakly prime, because it can be changed into another prime (21335155663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10667577821 + 10667577822.

It is an arithmetic number, because the mean of its divisors is an integer number (10667577822).

Almost surely, 2^21335155643 is an apocalyptic number.

21335155643 is a deficient number, since it is larger than the sum of its proper divisors (1).

21335155643 is an equidigital number, since it uses as much as digits as its factorization.

21335155643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 162000, while the sum is 38.

The spelling of 21335155643 in words is "twenty-one billion, three hundred thirty-five million, one hundred fifty-five thousand, six hundred forty-three".