51781315 has 16 divisors (see below), whose sum is σ = 65882880. Its totient is φ = 39000960.

The previous prime is 51781313. The next prime is 51781333. The reversal of 51781315 is 51318715.

51781315 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 51781315 - 2¹ = 51781313 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is not an unprimeable number, because it can be changed into a prime (51781313) 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 15 ways as a sum of consecutive naturals, for example, 1221 + ... + 10249.

It is an arithmetic number, because the mean of its divisors is an integer number (4117680).

Almost surely, 2^51781315 is an apocalyptic number.

51781315 is a deficient number, since it is larger than the sum of its proper divisors (14101565).

51781315 is a wasteful number, since it uses less digits than its factorization.

51781315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9102.

The product of its digits is 4200, while the sum is 31.

The square root of 51781315 is about 7195.9234987596. The cubic root of 51781315 is about 372.7271470174.

The spelling of 51781315 in words is "fifty-one million, seven hundred eighty-one thousand, three hundred fifteen".