51321647 has 16 divisors (see below), whose sum is σ = 57372672. Its totient is φ = 45588960.

The previous prime is 51321643. The next prime is 51321653. The reversal of 51321647 is 74612315.

It is a cyclic number.

It is not a de Polignac number, because 51321647 - 2² = 51321643 is a prime.

It is a super-2 number, since 2×51321647² = 5267822901585218, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51321643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139658 + ... + 140024.

It is an arithmetic number, because the mean of its divisors is an integer number (3585792).

Almost surely, 2^51321647 is an apocalyptic number.

51321647 is a deficient number, since it is larger than the sum of its proper divisors (6051025).

51321647 is a wasteful number, since it uses less digits than its factorization.

51321647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758.

The product of its digits is 5040, while the sum is 29.

The square root of 51321647 is about 7163.9128274987. The cubic root of 51321647 is about 371.6209550069.

The spelling of 51321647 in words is "fifty-one million, three hundred twenty-one thousand, six hundred forty-seven".