21311333331 has 16 divisors (see below), whose sum is σ = 30089771424. Its totient is φ = 13370402304.

The previous prime is 21311333321. The next prime is 21311333341. The reversal of 21311333331 is 13333311312.

It is an interprime number because it is at equal distance from previous prime (21311333321) and next prime (21311333341).

It is a de Polignac number, because none of the positive numbers 2^k-21311333331 is a prime.

It is a super-2 number, since 2×21311333331² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21311333311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 683085 + ... + 713601.

It is an arithmetic number, because the mean of its divisors is an integer number (1880610714).

Almost surely, 2^21311333331 is an apocalyptic number.

21311333331 is a deficient number, since it is larger than the sum of its proper divisors (8778438093).

21311333331 is a wasteful number, since it uses less digits than its factorization.

21311333331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44230.

The product of its digits is 1458, while the sum is 24.

Adding to 21311333331 its reverse (13333311312), we get a palindrome (34644644643).

The spelling of 21311333331 in words is "twenty-one billion, three hundred eleven million, three hundred thirty-three thousand, three hundred thirty-one".