51581405 has 4 divisors (see below), whose sum is σ = 61897692. Its totient is φ = 41265120.

The previous prime is 51581393. The next prime is 51581423. The reversal of 51581405 is 50418515.

51581405 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.

It can be written as a sum of positive squares in 2 ways, for example, as 5924356 + 45657049 = 2434^2 + 6757^2 .

It is not a de Polignac number, because 51581405 - 2⁸ = 51581149 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5158136 + ... + 5158145.

It is an arithmetic number, because the mean of its divisors is an integer number (15474423).

Almost surely, 2^51581405 is an apocalyptic number.

It is an amenable number.

51581405 is a deficient number, since it is larger than the sum of its proper divisors (10316287).

51581405 is a wasteful number, since it uses less digits than its factorization.

51581405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10316286.

The product of its (nonzero) digits is 4000, while the sum is 29.

The square root of 51581405 is about 7182.0195627692. The cubic root of 51581405 is about 372.2468709534.

The spelling of 51581405 in words is "fifty-one million, five hundred eighty-one thousand, four hundred five".