51191864 has 8 divisors (see below), whose sum is σ = 95984760. Its totient is φ = 25595928.

The previous prime is 51191851. The next prime is 51191867. The reversal of 51191864 is 46819115.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51191867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3199484 + ... + 3199499.

It is an arithmetic number, because the mean of its divisors is an integer number (11998095).

Almost surely, 2^51191864 is an apocalyptic number.

It is an amenable number.

51191864 is a deficient number, since it is larger than the sum of its proper divisors (44792896).

51191864 is a wasteful number, since it uses less digits than its factorization.

51191864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6398989 (or 6398985 counting only the distinct ones).

The product of its digits is 8640, while the sum is 35.

The square root of 51191864 is about 7154.8489851289. The cubic root of 51191864 is about 371.3074369144.

The spelling of 51191864 in words is "fifty-one million, one hundred ninety-one thousand, eight hundred sixty-four".