20534543149 has 4 divisors (see below), whose sum is σ = 20538243964. Its totient is φ = 20530842336.

The previous prime is 20534543011. The next prime is 20534543153. The reversal of 20534543149 is 94134543502.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14537124900 + 5997418249 = 120570^2 + 77443^2 .

It is a cyclic number.

It is not a de Polignac number, because 20534543149 - 2¹⁹ = 20534018861 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 (20534541149) 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, 1842072 + ... + 1853185.

It is an arithmetic number, because the mean of its divisors is an integer number (5134560991).

Almost surely, 2^20534543149 is an apocalyptic number.

It is an amenable number.

20534543149 is a deficient number, since it is larger than the sum of its proper divisors (3700815).

20534543149 is an equidigital number, since it uses as much as digits as its factorization.

20534543149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3700814.

The product of its (nonzero) digits is 259200, while the sum is 40.

The spelling of 20534543149 in words is "twenty billion, five hundred thirty-four million, five hundred forty-three thousand, one hundred forty-nine".