51078212391 has 16 divisors (see below), whose sum is σ = 68267420928. Its totient is φ = 33970622400.

The previous prime is 51078212369. The next prime is 51078212413. The reversal of 51078212391 is 19321287015.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (51078212369) and next prime (51078212413).

It is not a de Polignac number, because 51078212391 - 2⁶ = 51078212327 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51078219391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7551451 + ... + 7558211.

It is an arithmetic number, because the mean of its divisors is an integer number (4266713808).

Almost surely, 2^51078212391 is an apocalyptic number.

51078212391 is a deficient number, since it is larger than the sum of its proper divisors (17189208537).

51078212391 is a wasteful number, since it uses less digits than its factorization.

51078212391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12422.

The product of its (nonzero) digits is 30240, while the sum is 39.

The spelling of 51078212391 in words is "fifty-one billion, seventy-eight million, two hundred twelve thousand, three hundred ninety-one".