21205533139 has 8 divisors (see below), whose sum is σ = 24236016480. Its totient is φ = 18175330176.

The previous prime is 21205533109. The next prime is 21205533143. The reversal of 21205533139 is 93133550212.

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 21205533139 - 2¹¹ = 21205531091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21205533109) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130107 + ... + 243595.

It is an arithmetic number, because the mean of its divisors is an integer number (3029502060).

Almost surely, 2^21205533139 is an apocalyptic number.

21205533139 is a deficient number, since it is larger than the sum of its proper divisors (3030483341).

21205533139 is a wasteful number, since it uses less digits than its factorization.

21205533139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140189.

The product of its (nonzero) digits is 24300, while the sum is 34.

The spelling of 21205533139 in words is "twenty-one billion, two hundred five million, five hundred thirty-three thousand, one hundred thirty-nine".