51397647 has 16 divisors (see below), whose sum is σ = 82927872. Its totient is φ = 27642240.

The previous prime is 51397639. The next prime is 51397669. The reversal of 51397647 is 74679315.

It is not a de Polignac number, because 51397647 - 2³ = 51397639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51397599 and 51397608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51397607) 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, 71629 + ... + 72342.

It is an arithmetic number, because the mean of its divisors is an integer number (5182992).

Almost surely, 2^51397647 is an apocalyptic number.

51397647 is a deficient number, since it is larger than the sum of its proper divisors (31530225).

51397647 is a wasteful number, since it uses less digits than its factorization.

51397647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143998.

The product of its digits is 158760, while the sum is 42.

The square root of 51397647 is about 7169.2152290191. The cubic root of 51397647 is about 371.8043036478.

The spelling of 51397647 in words is "fifty-one million, three hundred ninety-seven thousand, six hundred forty-seven".