21311040243155 has 8 divisors (see below), whose sum is σ = 27540421237392. Its totient is φ = 15737383564128.

The previous prime is 21311040243149. The next prime is 21311040243179. The reversal of 21311040243155 is 55134204011312.

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 21311040243155 - 2¹⁶ = 21311040177619 is a prime.

It is a Duffinian number.

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, 163931078729 + ... + 163931078858.

It is an arithmetic number, because the mean of its divisors is an integer number (3442552654674).

Almost surely, 2^{21311040243155} is an apocalyptic number.

21311040243155 is a deficient number, since it is larger than the sum of its proper divisors (6229380994237).

21311040243155 is a wasteful number, since it uses less digits than its factorization.

21311040243155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327862157605.

The product of its (nonzero) digits is 14400, while the sum is 32.

Adding to 21311040243155 its reverse (55134204011312), we get a palindrome (76445244254467).

The spelling of 21311040243155 in words is "twenty-one trillion, three hundred eleven billion, forty million, two hundred forty-three thousand, one hundred fifty-five".