51205235321 has 4 divisors (see below), whose sum is σ = 51702373632. Its totient is φ = 50708097012.

The previous prime is 51205235299. The next prime is 51205235357. The reversal of 51205235321 is 12353250215.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51205235321 is a prime.

It is a super-2 number, since 2×51205235321² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51205235021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 248569001 + ... + 248569206.

It is an arithmetic number, because the mean of its divisors is an integer number (12925593408).

Almost surely, 2^51205235321 is an apocalyptic number.

It is an amenable number.

51205235321 is a deficient number, since it is larger than the sum of its proper divisors (497138311).

51205235321 is a wasteful number, since it uses less digits than its factorization.

51205235321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497138310.

The product of its (nonzero) digits is 9000, while the sum is 29.

Adding to 51205235321 its reverse (12353250215), we get a palindrome (63558485536).

The spelling of 51205235321 in words is "fifty-one billion, two hundred five million, two hundred thirty-five thousand, three hundred twenty-one".