51011555 has 16 divisors (see below), whose sum is σ = 71108544. Its totient is φ = 34404480.

The previous prime is 51011549. The next prime is 51011557. The reversal of 51011555 is 55511015.

It is a happy number.

It is not a de Polignac number, because 51011555 - 2¹⁴ = 50995171 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51011555.

It is not an unprimeable number, because it can be changed into a prime (51011557) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9812 + ... + 14081.

It is an arithmetic number, because the mean of its divisors is an integer number (4444284).

Almost surely, 2^51011555 is an apocalyptic number.

51011555 is a deficient number, since it is larger than the sum of its proper divisors (20096989).

51011555 is a wasteful number, since it uses less digits than its factorization.

51011555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23966.

The product of its (nonzero) digits is 625, while the sum is 23.

The square root of 51011555 is about 7142.2373945424. The cubic root of 51011555 is about 370.8709819398.

The spelling of 51011555 in words is "fifty-one million, eleven thousand, five hundred fifty-five".