51265165657 has 4 divisors (see below), whose sum is σ = 53032930020. Its totient is φ = 49497401296.

The previous prime is 51265165649. The next prime is 51265165661. The reversal of 51265165657 is 75656156215.

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 33637027216 + 17628138441 = 183404^2 + 132771^2 .

It is a cyclic number.

It is not a de Polignac number, because 51265165657 - 2³ = 51265165649 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51265165657.

It is not an unprimeable number, because it can be changed into a prime (51265165687) 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, 883882138 + ... + 883882195.

It is an arithmetic number, because the mean of its divisors is an integer number (13258232505).

Almost surely, 2^51265165657 is an apocalyptic number.

It is an amenable number.

51265165657 is a deficient number, since it is larger than the sum of its proper divisors (1767764363).

51265165657 is a wasteful number, since it uses less digits than its factorization.

51265165657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1767764362.

The product of its digits is 1890000, while the sum is 49.

The spelling of 51265165657 in words is "fifty-one billion, two hundred sixty-five million, one hundred sixty-five thousand, six hundred fifty-seven".