51245405 has 4 divisors (see below), whose sum is σ = 61494492. Its totient is φ = 40996320.

The previous prime is 51245401. The next prime is 51245423. The reversal of 51245405 is 50454215.

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 26822041 + 24423364 = 5179^2 + 4942^2 .

It is not a de Polignac number, because 51245405 - 2² = 51245401 is a prime.

It is a super-2 number, since 2×51245405² = 5252183067228050, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51245401) 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, 5124536 + ... + 5124545.

It is an arithmetic number, because the mean of its divisors is an integer number (15373623).

Almost surely, 2^51245405 is an apocalyptic number.

It is an amenable number.

51245405 is a deficient number, since it is larger than the sum of its proper divisors (10249087).

51245405 is a wasteful number, since it uses less digits than its factorization.

51245405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10249086.

The product of its (nonzero) digits is 4000, while the sum is 26.

The square root of 51245405 is about 7158.5895957234. The cubic root of 51245405 is about 371.4368405809.

The spelling of 51245405 in words is "fifty-one million, two hundred forty-five thousand, four hundred five".