21355434066 has 32 divisors (see below), whose sum is σ = 45118872000. Its totient is φ = 6719811840.

The previous prime is 21355434053. The next prime is 21355434083. The reversal of 21355434066 is 66043455312.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 301291 + ... + 365358.

It is an arithmetic number, because the mean of its divisors is an integer number (1409964750).

Almost surely, 2^21355434066 is an apocalyptic number.

21355434066 is an abundant number, since it is smaller than the sum of its proper divisors (23763437934).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21355434066 is a wasteful number, since it uses less digits than its factorization.

21355434066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666954.

The product of its (nonzero) digits is 259200, while the sum is 39.

Adding to 21355434066 its reverse (66043455312), we get a palindrome (87398889378).

The spelling of 21355434066 in words is "twenty-one billion, three hundred fifty-five million, four hundred thirty-four thousand, sixty-six".