51205525405 has 4 divisors (see below), whose sum is σ = 61446630492. Its totient is φ = 40964420320.

The previous prime is 51205525387. The next prime is 51205525421. The reversal of 51205525405 is 50452550215.

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 29442784921 + 21762740484 = 171589^2 + 147522^2 .

It is not a de Polignac number, because 51205525405 - 2¹¹ = 51205523357 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, 5120552536 + ... + 5120552545.

It is an arithmetic number, because the mean of its divisors is an integer number (15361657623).

Almost surely, 2^51205525405 is an apocalyptic number.

It is an amenable number.

51205525405 is a deficient number, since it is larger than the sum of its proper divisors (10241105087).

51205525405 is a wasteful number, since it uses less digits than its factorization.

51205525405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10241105086.

The product of its (nonzero) digits is 50000, while the sum is 34.

The spelling of 51205525405 in words is "fifty-one billion, two hundred five million, five hundred twenty-five thousand, four hundred five".