21355434065 has 24 divisors (see below), whose sum is σ = 29831374080. Its totient is φ = 14633444448.

The previous prime is 21355434053. The next prime is 21355434083. The reversal of 21355434065 is 56043455312.

It is not a de Polignac number, because 21355434065 - 2⁴ = 21355434049 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 327584 + ... + 387326.

It is an arithmetic number, because the mean of its divisors is an integer number (1242973920).

Almost surely, 2^21355434065 is an apocalyptic number.

It is an amenable number.

21355434065 is a deficient number, since it is larger than the sum of its proper divisors (8475940015).

21355434065 is a wasteful number, since it uses less digits than its factorization.

21355434065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61221 (or 61214 counting only the distinct ones).

The product of its (nonzero) digits is 216000, while the sum is 38.

Adding to 21355434065 its reverse (56043455312), we get a palindrome (77398889377).

The spelling of 21355434065 in words is "twenty-one billion, three hundred fifty-five million, four hundred thirty-four thousand, sixty-five".