51020405 has 4 divisors (see below), whose sum is σ = 61224492. Its totient is φ = 40816320.

The previous prime is 51020399. The next prime is 51020413. The reversal of 51020405 is 50402015.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50402015 = 5 ⋅10080403.

It can be written as a sum of positive squares in 2 ways, for example, as 24990001 + 26030404 = 4999^2 + 5102^2 .

It is not a de Polignac number, because 51020405 - 2⁶ = 51020341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5102036 + ... + 5102045.

It is an arithmetic number, because the mean of its divisors is an integer number (15306123).

Almost surely, 2^51020405 is an apocalyptic number.

It is an amenable number.

51020405 is a deficient number, since it is larger than the sum of its proper divisors (10204087).

51020405 is a wasteful number, since it uses less digits than its factorization.

51020405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10204086.

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 51020405 is about 7142.8569214286. The cubic root of 51020405 is about 370.8924281814.

The spelling of 51020405 in words is "fifty-one million, twenty thousand, four hundred five".