51186421 has 16 divisors (see below), whose sum is σ = 62213760. Its totient is φ = 41469120.

The previous prime is 51186413. The next prime is 51186427. The reversal of 51186421 is 12468115.

51186421 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 51186421 - 2³ = 51186413 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 51186421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51186427) 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, 2025 + ... + 10318.

It is an arithmetic number, because the mean of its divisors is an integer number (3888360).

Almost surely, 2^51186421 is an apocalyptic number.

It is an amenable number.

51186421 is a deficient number, since it is larger than the sum of its proper divisors (11027339).

51186421 is a wasteful number, since it uses less digits than its factorization.

51186421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12396.

The product of its digits is 1920, while the sum is 28.

The square root of 51186421 is about 7154.4686036071. The cubic root of 51186421 is about 371.2942766330.

The spelling of 51186421 in words is "fifty-one million, one hundred eighty-six thousand, four hundred twenty-one".