51491395 has 16 divisors (see below), whose sum is σ = 62868960. Its totient is φ = 40480000.

The previous prime is 51491393. The next prime is 51491399. The reversal of 51491395 is 59319415.

It is a happy number.

It is not a de Polignac number, because 51491395 - 2¹ = 51491393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51491393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111465 + ... + 111925.

It is an arithmetic number, because the mean of its divisors is an integer number (3929310).

Almost surely, 2^51491395 is an apocalyptic number.

51491395 is a deficient number, since it is larger than the sum of its proper divisors (11377565).

51491395 is a wasteful number, since it uses less digits than its factorization.

51491395 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 806.

The product of its digits is 24300, while the sum is 37.

The square root of 51491395 is about 7175.7504833989. The cubic root of 51491395 is about 372.0302202104.

The spelling of 51491395 in words is "fifty-one million, four hundred ninety-one thousand, three hundred ninety-five".