51778 has 4 divisors (see below), whose sum is σ = 77670. Its totient is φ = 25888.

The previous prime is 51769. The next prime is 51787. The reversal of 51778 is 87715.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (51769) and next prime (51787).

It can be written as a sum of positive squares in only one way, i.e., 31329 + 20449 = 177^2 + 143^2 .

It is a super-2 number, since 2×51778² = 5361922568, which contains 22 as substring.

It is a nialpdrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12943 + ... + 12946.

2⁵¹⁷⁷⁸ is an apocalyptic number.

51778 is a deficient number, since it is larger than the sum of its proper divisors (25892).

51778 is a wasteful number, since it uses less digits than its factorization.

51778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25891.

The product of its digits is 1960, while the sum is 28.

The square root of 51778 is about 227.5477971768. The cubic root of 51778 is about 37.2719192946.

Subtracting 51778 from its reverse (87715), we obtain a cube (35937 = 33³).

It can be divided in two parts, 517 and 78, that added together give a palindrome (595).

The spelling of 51778 in words is "fifty-one thousand, seven hundred seventy-eight".