51158900861 has 4 divisors (see below), whose sum is σ = 51164871324. Its totient is φ = 51152930400.

The previous prime is 51158900839. The next prime is 51158900867. The reversal of 51158900861 is 16800985115.

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 24063765625 + 27095135236 = 155125^2 + 164606^2 .

It is a cyclic number.

It is not a de Polignac number, because 51158900861 - 2¹⁸ = 51158638717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51158900867) 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, 2972360 + ... + 2989521.

It is an arithmetic number, because the mean of its divisors is an integer number (12791217831).

Almost surely, 2^51158900861 is an apocalyptic number.

It is an amenable number.

51158900861 is a deficient number, since it is larger than the sum of its proper divisors (5970463).

51158900861 is an equidigital number, since it uses as much as digits as its factorization.

51158900861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5970462.

The product of its (nonzero) digits is 86400, while the sum is 44.

The spelling of 51158900861 in words is "fifty-one billion, one hundred fifty-eight million, nine hundred thousand, eight hundred sixty-one".