21623556500543 has 4 divisors (see below), whose sum is σ = 21632793391608. Its totient is φ = 21614319609480.

The previous prime is 21623556500477. The next prime is 21623556500593. The reversal of 21623556500543 is 34500565532612.

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 21623556500543 - 2²⁴ = 21623539723327 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 (21623556500593) 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, 4618442021 + ... + 4618446702.

It is an arithmetic number, because the mean of its divisors is an integer number (5408198347902).

Almost surely, 2^{21623556500543} is an apocalyptic number.

21623556500543 is a deficient number, since it is larger than the sum of its proper divisors (9236891065).

21623556500543 is an equidigital number, since it uses as much as digits as its factorization.

21623556500543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9236891064.

The product of its (nonzero) digits is 3240000, while the sum is 47.

The spelling of 21623556500543 in words is "twenty-one trillion, six hundred twenty-three billion, five hundred fifty-six million, five hundred thousand, five hundred forty-three".