51205232605 has 4 divisors (see below), whose sum is σ = 61446279132. Its totient is φ = 40964186080.

The previous prime is 51205232597. The next prime is 51205232621. The reversal of 51205232605 is 50623250215.

It is a happy number.

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 5420787876 + 45784444729 = 73626^2 + 213973^2 .

It is not a de Polignac number, because 51205232605 - 2³ = 51205232597 is a prime.

It is a super-2 number, since 2×51205232605² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 5120523256 + ... + 5120523265.

It is an arithmetic number, because the mean of its divisors is an integer number (15361569783).

Almost surely, 2^51205232605 is an apocalyptic number.

It is an amenable number.

51205232605 is a deficient number, since it is larger than the sum of its proper divisors (10241046527).

51205232605 is a wasteful number, since it uses less digits than its factorization.

51205232605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10241046526.

The product of its (nonzero) digits is 18000, while the sum is 31.

The spelling of 51205232605 in words is "fifty-one billion, two hundred five million, two hundred thirty-two thousand, six hundred five".