51378855 has 32 divisors (see below), whose sum is σ = 90402048. Its totient is φ = 24710400.

The previous prime is 51378853. The next prime is 51378881. The reversal of 51378855 is 55887315.

It is a happy number.

It is not a de Polignac number, because 51378855 - 2¹ = 51378853 is a prime.

It is a super-2 number, since 2×51378855² = 5279573482222050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51378853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20427 + ... + 22803.

It is an arithmetic number, because the mean of its divisors is an integer number (2825064).

Almost surely, 2^51378855 is an apocalyptic number.

51378855 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

51378855 is a deficient number, since it is larger than the sum of its proper divisors (39023193).

51378855 is a wasteful number, since it uses less digits than its factorization.

51378855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2527.

The product of its digits is 168000, while the sum is 42.

The square root of 51378855 is about 7167.9045055023. The cubic root of 51378855 is about 371.7589851129.

The spelling of 51378855 in words is "fifty-one million, three hundred seventy-eight thousand, eight hundred fifty-five".