51051567205721 has 4 divisors (see below), whose sum is σ = 51441273825744. Its totient is φ = 50661860585700.

The previous prime is 51051567205693. The next prime is 51051567205741. The reversal of 51051567205721 is 12750276515015.

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 not a de Polignac number, because 51051567205721 - 2⁶ = 51051567205657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51051567205741) 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, 194853309815 + ... + 194853310076.

It is an arithmetic number, because the mean of its divisors is an integer number (12860318456436).

Almost surely, 2^{51051567205721} is an apocalyptic number.

It is an amenable number.

51051567205721 is a deficient number, since it is larger than the sum of its proper divisors (389706620023).

51051567205721 is a wasteful number, since it uses less digits than its factorization.

51051567205721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389706620022.

The product of its (nonzero) digits is 735000, while the sum is 47.

The spelling of 51051567205721 in words is "fifty-one trillion, fifty-one billion, five hundred sixty-seven million, two hundred five thousand, seven hundred twenty-one".