21002112331 has 4 divisors (see below), whose sum is σ = 21490533592. Its totient is φ = 20513691072.

The previous prime is 21002112277. The next prime is 21002112343. The reversal of 21002112331 is 13321120012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21002112331 - 2⁷ = 21002112203 is a prime.

It is a super-2 number, since 2×21002112331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002112371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 244210566 + ... + 244210651.

It is an arithmetic number, because the mean of its divisors is an integer number (5372633398).

Almost surely, 2^21002112331 is an apocalyptic number.

21002112331 is a deficient number, since it is larger than the sum of its proper divisors (488421261).

21002112331 is an equidigital number, since it uses as much as digits as its factorization.

21002112331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488421260.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21002112331 its reverse (13321120012), we get a palindrome (34323232343).

The spelling of 21002112331 in words is "twenty-one billion, two million, one hundred twelve thousand, three hundred thirty-one".