51626815781265 has 80 divisors (see below), whose sum is σ = 98338442487120. Its totient is φ = 25822413066240.

The previous prime is 51626815781257. The next prime is 51626815781287. The reversal of 51626815781265 is 56218751862615.

51626815781265 is a `hidden beast` number, since 5 + 16 + 26 + 8 + 1 + 578 + 1 + 26 + 5 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 667948232961 + 50958867548304 = 817281^2 + 7138548^2 .

It is not a de Polignac number, because 51626815781265 - 2³ = 51626815781257 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 11407750 + ... + 15277119.

It is an arithmetic number, because the mean of its divisors is an integer number (1229230531089).

Almost surely, 2^{51626815781265} is an apocalyptic number.

It is an amenable number.

51626815781265 is a deficient number, since it is larger than the sum of its proper divisors (46711626705855).

51626815781265 is a wasteful number, since it uses less digits than its factorization.

51626815781265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26685184 (or 26685175 counting only the distinct ones).

The product of its digits is 48384000, while the sum is 63.

The spelling of 51626815781265 in words is "fifty-one trillion, six hundred twenty-six billion, eight hundred fifteen million, seven hundred eighty-one thousand, two hundred sixty-five".