21355655312 has 20 divisors (see below), whose sum is σ = 41674259760.
Its totient is φ = 10601007648.
The previous prime is 21355655311. The next prime is 21355655351.
21355655312 is nontrivially palindromic in base 10.
It is not an unprimeable number, because it can be changed into a prime (21355655311) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4798958 + ... + 4803405.
It is an arithmetic number, because the mean of its divisors is an integer number (2083712988).
Almost surely, 221355655312 is an apocalyptic number.
It is an amenable number.
21355655312 is a deficient number, since it is larger than the sum of its proper divisors (20318604448).
21355655312 is a wasteful number, since it uses less digits than its factorization.
21355655312 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 9602510 (or 9602504 counting only the distinct ones).
The product of its digits is 135000, while the sum is 38.
The spelling of 21355655312 in words is "twenty-one billion, three hundred fifty-five million, six hundred fifty-five thousand, three hundred twelve".