51155555 has 8 divisors (see below), whose sum is σ = 66967344. Its totient is φ = 37204000.

The previous prime is 51155551. The next prime is 51155561. The reversal of 51155555 is 55555115.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51155555 - 2² = 51155551 is a prime.

It is a nude number because it is divisible by every one of its digits.

It is a Duffinian number.

51155555 is a modest number, since divided by 5555 gives 5115 as remainder.

It is not an unprimeable number, because it can be changed into a prime (51155551) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 464996 + ... + 465105.

It is an arithmetic number, because the mean of its divisors is an integer number (8370918).

Almost surely, 2^51155555 is an apocalyptic number.

51155555 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

51155555 is a deficient number, since it is larger than the sum of its proper divisors (15811789).

51155555 is a wasteful number, since it uses less digits than its factorization.

51155555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 930117.

The product of its digits is 15625, while the sum is 32.

The square root of 51155555 is about 7152.3111649312. The cubic root of 51155555 is about 371.2196300551.

It can be divided in two parts, 5 and 1155555, that multiplied together give a palindrome (5777775).

The spelling of 51155555 in words is "fifty-one million, one hundred fifty-five thousand, five hundred fifty-five".