21031434543 has 16 divisors (see below), whose sum is σ = 32050066176. Its totient is φ = 12017150400.

The previous prime is 21031434527. The next prime is 21031434581. The reversal of 21031434543 is 34543413012.

It is not a de Polignac number, because 21031434543 - 2⁴ = 21031434527 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21031434543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031434443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 435955 + ... + 481787.

It is an arithmetic number, because the mean of its divisors is an integer number (2003129136).

Almost surely, 2^21031434543 is an apocalyptic number.

21031434543 is a deficient number, since it is larger than the sum of its proper divisors (11018631633).

21031434543 is a wasteful number, since it uses less digits than its factorization.

21031434543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67694.

The product of its (nonzero) digits is 17280, while the sum is 30.

Adding to 21031434543 its reverse (34543413012), we get a palindrome (55574847555).

The spelling of 21031434543 in words is "twenty-one billion, thirty-one million, four hundred thirty-four thousand, five hundred forty-three".