21010145543 has 4 divisors (see below), whose sum is σ = 21218166888. Its totient is φ = 20802124200.

The previous prime is 21010145537. The next prime is 21010145609. The reversal of 21010145543 is 34554101012.

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 21010145543 - 2⁶ = 21010145479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010145503) 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, 104010521 + ... + 104010722.

It is an arithmetic number, because the mean of its divisors is an integer number (5304541722).

Almost surely, 2^21010145543 is an apocalyptic number.

21010145543 is a deficient number, since it is larger than the sum of its proper divisors (208021345).

21010145543 is a wasteful number, since it uses less digits than its factorization.

21010145543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208021344.

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21010145543 its reverse (34554101012), we get a palindrome (55564246555).

The spelling of 21010145543 in words is "twenty-one billion, ten million, one hundred forty-five thousand, five hundred forty-three".