51405320 has 32 divisors (see below), whose sum is σ = 115867800. Its totient is φ = 20525568.

The previous prime is 51405271. The next prime is 51405337. The reversal of 51405320 is 2350415.

It can be written as a sum of positive squares in 4 ways, for example, as 50951044 + 454276 = 7138^2 + 674^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 51405292 and 51405301.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39236 + ... + 40524.

Almost surely, 2^51405320 is an apocalyptic number.

It is an amenable number.

51405320 is an abundant number, since it is smaller than the sum of its proper divisors (64462480).

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

51405320 is a wasteful number, since it uses less digits than its factorization.

51405320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2297 (or 2293 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 51405320 is about 7169.7503443286. The cubic root of 51405320 is about 371.8228045756.

Adding to 51405320 its reverse (2350415), we get a palindrome (53755735).

The spelling of 51405320 in words is "fifty-one million, four hundred five thousand, three hundred twenty".