51311405 has 4 divisors (see below), whose sum is σ = 61573692. Its totient is φ = 41049120.

The previous prime is 51311401. The next prime is 51311441. The reversal of 51311405 is 50411315.

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 19377604 + 31933801 = 4402^2 + 5651^2 .

It is not a de Polignac number, because 51311405 - 2² = 51311401 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 (51311401) 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, 5131136 + ... + 5131145.

It is an arithmetic number, because the mean of its divisors is an integer number (15393423).

Almost surely, 2^51311405 is an apocalyptic number.

It is an amenable number.

51311405 is a deficient number, since it is larger than the sum of its proper divisors (10262287).

51311405 is a wasteful number, since it uses less digits than its factorization.

51311405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10262286.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 51311405 is about 7163.1979590124. The cubic root of 51311405 is about 371.5962325278.

The spelling of 51311405 in words is "fifty-one million, three hundred eleven thousand, four hundred five".