51021556874 has 4 divisors (see below), whose sum is σ = 76532335314. Its totient is φ = 25510778436.

The previous prime is 51021556871. The next prime is 51021556879. The reversal of 51021556874 is 47865512015.

51021556874 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 47865512015 = 5 ⋅9573102403.

It can be written as a sum of positive squares in only one way, i.e., 49971472849 + 1050084025 = 223543^2 + 32405^2 .

It is not an unprimeable number, because it can be changed into a prime (51021556871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12755389217 + ... + 12755389220.

Almost surely, 2^51021556874 is an apocalyptic number.

51021556874 is a deficient number, since it is larger than the sum of its proper divisors (25510778440).

51021556874 is a wasteful number, since it uses less digits than its factorization.

51021556874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25510778439.

The product of its (nonzero) digits is 336000, while the sum is 44.

The spelling of 51021556874 in words is "fifty-one billion, twenty-one million, five hundred fifty-six thousand, eight hundred seventy-four".