51091897122 has 270 divisors, whose sum is σ = 138694111083. Its totient is φ = 14016539376.

The previous prime is 51091897117. The next prime is 51091897139. The reversal of 51091897122 is 22179819015.

51091897122 is a `hidden beast` number, since 510 + 9 + 1 + 8 + 9 + 7 + 122 = 666.

51091897122 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 25545948561 + 25545948561 = 159831^2 + 159831^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=159831.

It is a super-2 number, since 2×51091897122² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 865964329 + ... + 865964387.

Almost surely, 2^51091897122 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51091897122

51091897122 is an abundant number, since it is smaller than the sum of its proper divisors (87602213961).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51091897122 is an equidigital number, since it uses as much as digits as its factorization.

51091897122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 45.

The spelling of 51091897122 in words is "fifty-one billion, ninety-one million, eight hundred ninety-seven thousand, one hundred twenty-two".