21305353233 has 16 divisors (see below), whose sum is σ = 29194742720. Its totient is φ = 13812652224.

The previous prime is 21305353231. The next prime is 21305353243. The reversal of 21305353233 is 33235350312.

It is not a de Polignac number, because 21305353233 - 2¹ = 21305353231 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21305353233.

It is not an unprimeable number, because it can be changed into a prime (21305353231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 331066 + ... + 390147.

It is an arithmetic number, because the mean of its divisors is an integer number (1824671420).

Almost surely, 2^21305353233 is an apocalyptic number.

It is an amenable number.

21305353233 is a deficient number, since it is larger than the sum of its proper divisors (7889389487).

21305353233 is a wasteful number, since it uses less digits than its factorization.

21305353233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721488.

The product of its (nonzero) digits is 24300, while the sum is 30.

The spelling of 21305353233 in words is "twenty-one billion, three hundred five million, three hundred fifty-three thousand, two hundred thirty-three".