51268810561 has 4 divisors (see below), whose sum is σ = 51351636400. Its totient is φ = 51185984724.

The previous prime is 51268810547. The next prime is 51268810589. The reversal of 51268810561 is 16501886215.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16501886215 = 5 ⋅3300377243.

It is a cyclic number.

It is not a de Polignac number, because 51268810561 - 2⁷ = 51268810433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51268810501) 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, 41411991 + ... + 41413228.

It is an arithmetic number, because the mean of its divisors is an integer number (12837909100).

Almost surely, 2^51268810561 is an apocalyptic number.

It is an amenable number.

51268810561 is a deficient number, since it is larger than the sum of its proper divisors (82825839).

51268810561 is an equidigital number, since it uses as much as digits as its factorization.

51268810561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82825838.

The product of its (nonzero) digits is 115200, while the sum is 43.

The spelling of 51268810561 in words is "fifty-one billion, two hundred sixty-eight million, eight hundred ten thousand, five hundred sixty-one".