51128863 has 4 divisors (see below), whose sum is σ = 51292528. Its totient is φ = 50965200.

The previous prime is 51128807. The next prime is 51128897. The reversal of 51128863 is 36882115.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36882115 = 5 ⋅7376423.

It is a cyclic number.

It is not a de Polignac number, because 51128863 - 2²¹ = 49031711 is a prime.

It is a super-2 number, since 2×51128863² = 5228321263345538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51128963) 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, 81363 + ... + 81988.

It is an arithmetic number, because the mean of its divisors is an integer number (12823132).

Almost surely, 2^51128863 is an apocalyptic number.

51128863 is a deficient number, since it is larger than the sum of its proper divisors (163665).

51128863 is a wasteful number, since it uses less digits than its factorization.

51128863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163664.

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

The square root of 51128863 is about 7150.4449511901. Note that the first 3 decimals coincide. The cubic root of 51128863 is about 371.1550536975.

The spelling of 51128863 in words is "fifty-one million, one hundred twenty-eight thousand, eight hundred sixty-three".