51238861 has 4 divisors (see below), whose sum is σ = 51438492. Its totient is φ = 51039232.

The previous prime is 51238819. The next prime is 51238879. The reversal of 51238861 is 16883215.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16883215 = 5 ⋅3376643.

It can be written as a sum of positive squares in 2 ways, for example, as 42653961 + 8584900 = 6531^2 + 2930^2 .

It is a cyclic number.

It is not a de Polignac number, because 51238861 - 2⁹ = 51238349 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 (51238261) 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, 99430 + ... + 99943.

It is an arithmetic number, because the mean of its divisors is an integer number (12859623).

Almost surely, 2^51238861 is an apocalyptic number.

It is an amenable number.

51238861 is a deficient number, since it is larger than the sum of its proper divisors (199631).

51238861 is a wasteful number, since it uses less digits than its factorization.

51238861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199630.

The product of its digits is 11520, while the sum is 34.

The square root of 51238861 is about 7158.1325078543. The cubic root of 51238861 is about 371.4210291720.

The spelling of 51238861 in words is "fifty-one million, two hundred thirty-eight thousand, eight hundred sixty-one".