21155232311 has 8 divisors (see below), whose sum is σ = 21418320000. Its totient is φ = 20892340152.

The previous prime is 21155232299. The next prime is 21155232317. The reversal of 21155232311 is 11323255112.

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 21155232311 - 2⁶ = 21155232247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21155232317) 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, 175190 + ... + 270188.

It is an arithmetic number, because the mean of its divisors is an integer number (2677290000).

Almost surely, 2^21155232311 is an apocalyptic number.

21155232311 is a deficient number, since it is larger than the sum of its proper divisors (263087689).

21155232311 is an equidigital number, since it uses as much as digits as its factorization.

21155232311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97765.

The product of its digits is 1800, while the sum is 26.

Adding to 21155232311 its reverse (11323255112), we get a palindrome (32478487423).

The spelling of 21155232311 in words is "twenty-one billion, one hundred fifty-five million, two hundred thirty-two thousand, three hundred eleven".