51315155 has 4 divisors (see below), whose sum is σ = 61578192. Its totient is φ = 41052120.

The previous prime is 51315113. The next prime is 51315157. The reversal of 51315155 is 55151315.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 51315155 - 2⁸ = 51314899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51315157) 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, 5131511 + ... + 5131520.

It is an arithmetic number, because the mean of its divisors is an integer number (15394548).

Almost surely, 2^51315155 is an apocalyptic number.

51315155 is a deficient number, since it is larger than the sum of its proper divisors (10263037).

51315155 is a wasteful number, since it uses less digits than its factorization.

51315155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10263036.

The product of its digits is 1875, while the sum is 26.

The square root of 51315155 is about 7163.4597088279. The cubic root of 51315155 is about 371.6052847838.

The spelling of 51315155 in words is "fifty-one million, three hundred fifteen thousand, one hundred fifty-five".