51165221605 has 8 divisors (see below), whose sum is σ = 61404687000. Its totient is φ = 40927896576.

The previous prime is 51165221551. The next prime is 51165221609. The reversal of 51165221605 is 50612256115.

It can be written as a sum of positive squares in 4 ways, for example, as 1325105604 + 49840116001 = 36402^2 + 223249^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51165221605 - 2⁷ = 51165221477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51165221609) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 482020 + ... + 578509.

It is an arithmetic number, because the mean of its divisors is an integer number (7675585875).

Almost surely, 2^51165221605 is an apocalyptic number.

It is an amenable number.

51165221605 is a deficient number, since it is larger than the sum of its proper divisors (10239465395).

51165221605 is a wasteful number, since it uses less digits than its factorization.

51165221605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1070183.

The product of its (nonzero) digits is 18000, while the sum is 34.

The spelling of 51165221605 in words is "fifty-one billion, one hundred sixty-five million, two hundred twenty-one thousand, six hundred five".