20211523543 has 4 divisors (see below), whose sum is σ = 21275287960. Its totient is φ = 19147759128.

The previous prime is 20211523531. The next prime is 20211523547. The reversal of 20211523543 is 34532511202.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20211523543 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 (20211523547) 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, 531882180 + ... + 531882217.

It is an arithmetic number, because the mean of its divisors is an integer number (5318821990).

Almost surely, 2^20211523543 is an apocalyptic number.

20211523543 is a deficient number, since it is larger than the sum of its proper divisors (1063764417).

20211523543 is a wasteful number, since it uses less digits than its factorization.

20211523543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1063764416.

The product of its (nonzero) digits is 7200, while the sum is 28.

The spelling of 20211523543 in words is "twenty billion, two hundred eleven million, five hundred twenty-three thousand, five hundred forty-three".