21331616531231 has 4 divisors (see below), whose sum is σ = 21474781743000. Its totient is φ = 21188451319464.

The previous prime is 21331616531213. The next prime is 21331616531371. The reversal of 21331616531231 is 13213561613312.

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 21331616531231 - 2²² = 21331612336927 is a prime.

It is a super-2 number, since 2×21331616531231² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331616531201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71582605661 + ... + 71582605958.

It is an arithmetic number, because the mean of its divisors is an integer number (5368695435750).

Almost surely, 2^{21331616531231} is an apocalyptic number.

21331616531231 is a deficient number, since it is larger than the sum of its proper divisors (143165211769).

21331616531231 is a wasteful number, since it uses less digits than its factorization.

21331616531231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143165211768.

The product of its digits is 58320, while the sum is 38.

The spelling of 21331616531231 in words is "twenty-one trillion, three hundred thirty-one billion, six hundred sixteen million, five hundred thirty-one thousand, two hundred thirty-one".