20543828405 has 4 divisors (see below), whose sum is σ = 24652594092. Its totient is φ = 16435062720.

The previous prime is 20543828387. The next prime is 20543828423. The reversal of 20543828405 is 50482834502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50482834502 = 2 ⋅25241417251.

It is an interprime number because it is at equal distance from previous prime (20543828387) and next prime (20543828423).

It can be written as a sum of positive squares in 2 ways, for example, as 11887758961 + 8656069444 = 109031^2 + 93038^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20543828405 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2054382836 + ... + 2054382845.

It is an arithmetic number, because the mean of its divisors is an integer number (6163148523).

Almost surely, 2^20543828405 is an apocalyptic number.

It is an amenable number.

20543828405 is a deficient number, since it is larger than the sum of its proper divisors (4108765687).

20543828405 is an equidigital number, since it uses as much as digits as its factorization.

20543828405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4108765686.

The product of its (nonzero) digits is 307200, while the sum is 41.

The spelling of 20543828405 in words is "twenty billion, five hundred forty-three million, eight hundred twenty-eight thousand, four hundred five".