21331601543 has 24 divisors (see below), whose sum is σ = 25866157680. Its totient is φ = 17518824960.

The previous prime is 21331601537. The next prime is 21331601617. The reversal of 21331601543 is 34510613312.

It is not a de Polignac number, because 21331601543 - 2¹² = 21331597447 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331601503) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 128855 + ... + 243447.

It is an arithmetic number, because the mean of its divisors is an integer number (1077756570).

Almost surely, 2^21331601543 is an apocalyptic number.

21331601543 is a deficient number, since it is larger than the sum of its proper divisors (4534556137).

21331601543 is a wasteful number, since it uses less digits than its factorization.

21331601543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114767 (or 114760 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 29.

The spelling of 21331601543 in words is "twenty-one billion, three hundred thirty-one million, six hundred one thousand, five hundred forty-three".