51155407 has 4 divisors (see below), whose sum is σ = 51856240. Its totient is φ = 50454576.

The previous prime is 51155387. The next prime is 51155443. The reversal of 51155407 is 70455115.

51155407 = 99² + 100² + ... + 536².

51155407 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 is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51155407 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 (51155477) by changing a digit.

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, 350307 + ... + 350452.

It is an arithmetic number, because the mean of its divisors is an integer number (12964060).

Almost surely, 2^51155407 is an apocalyptic number.

51155407 is a deficient number, since it is larger than the sum of its proper divisors (700833).

51155407 is an equidigital number, since it uses as much as digits as its factorization.

51155407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 700832.

The product of its (nonzero) digits is 3500, while the sum is 28.

The square root of 51155407 is about 7152.3008186177. The cubic root of 51155407 is about 371.2192720584.

The spelling of 51155407 in words is "fifty-one million, one hundred fifty-five thousand, four hundred seven".