51415555 has 4 divisors (see below), whose sum is σ = 61698672. Its totient is φ = 41132440.

The previous prime is 51415547. The next prime is 51415561. The reversal of 51415555 is 55551415.

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

It is not a de Polignac number, because 51415555 - 2³ = 51415547 is a prime.

It is a super-3 number, since 3×51415555³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5141551 + ... + 5141560.

It is an arithmetic number, because the mean of its divisors is an integer number (15424668).

Almost surely, 2^51415555 is an apocalyptic number.

51415555 is a deficient number, since it is larger than the sum of its proper divisors (10283117).

51415555 is a wasteful number, since it uses less digits than its factorization.

51415555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10283116.

The product of its digits is 12500, while the sum is 31.

The square root of 51415555 is about 7170.4640714531. The cubic root of 51415555 is about 371.8474800622.

It can be divided in two parts, 51 and 415555, that multiplied together give a triangular number (21193305 = T₆₅₁₀).

The spelling of 51415555 in words is "fifty-one million, four hundred fifteen thousand, five hundred fifty-five".