51145405 has 4 divisors (see below), whose sum is σ = 61374492. Its totient is φ = 40916320.

The previous prime is 51145403. The next prime is 51145417. The reversal of 51145405 is 50454115.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50454115 = 5 ⋅10090823.

It can be written as a sum of positive squares in 2 ways, for example, as 20376196 + 30769209 = 4514^2 + 5547^2 .

It is not a de Polignac number, because 51145405 - 2¹ = 51145403 is a prime.

It is a super-2 number, since 2×51145405² = 5231704905228050, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51145405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51145403) 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, 5114536 + ... + 5114545.

It is an arithmetic number, because the mean of its divisors is an integer number (15343623).

Almost surely, 2^51145405 is an apocalyptic number.

It is an amenable number.

51145405 is a deficient number, since it is larger than the sum of its proper divisors (10229087).

51145405 is a wasteful number, since it uses less digits than its factorization.

51145405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10229086.

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 51145405 is about 7151.6015688795. The cubic root of 51145405 is about 371.1950766547.

The spelling of 51145405 in words is "fifty-one million, one hundred forty-five thousand, four hundred five".