51781005 has 32 divisors (see below), whose sum is σ = 95032320. Its totient is φ = 26723520.

The previous prime is 51781003. The next prime is 51781021. The reversal of 51781005 is 50018715.

51781005 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51781005 - 2¹ = 51781003 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 51781005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51781003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2002 + ... + 10371.

It is an arithmetic number, because the mean of its divisors is an integer number (2969760).

Almost surely, 2^51781005 is an apocalyptic number.

It is an amenable number.

51781005 is a deficient number, since it is larger than the sum of its proper divisors (43251315).

51781005 is a wasteful number, since it uses less digits than its factorization.

51781005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12418 (or 12412 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 27.

The square root of 51781005 is about 7195.9019587540. The cubic root of 51781005 is about 372.7264032121.

The spelling of 51781005 in words is "fifty-one million, seven hundred eighty-one thousand, five".