21333781265 has 8 divisors (see below), whose sum is σ = 25601691840. Its totient is φ = 17066255472.

The previous prime is 21333781243. The next prime is 21333781291. The reversal of 21333781265 is 56218733312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21333781265 - 2⁶ = 21333781201 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44492 + ... + 211298.

It is an arithmetic number, because the mean of its divisors is an integer number (3200211480).

Almost surely, 2^21333781265 is an apocalyptic number.

It is an amenable number.

21333781265 is a deficient number, since it is larger than the sum of its proper divisors (4267910575).

21333781265 is a wasteful number, since it uses less digits than its factorization.

21333781265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192391.

The product of its digits is 181440, while the sum is 41.

The spelling of 21333781265 in words is "twenty-one billion, three hundred thirty-three million, seven hundred eighty-one thousand, two hundred sixty-five".