51217897 has 4 divisors (see below), whose sum is σ = 52467156. Its totient is φ = 49968640.

The previous prime is 51217891. The next prime is 51217927. The reversal of 51217897 is 79871215.

51217897 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79871215 = 5 ⋅15974243.

It can be written as a sum of positive squares in 2 ways, for example, as 18224361 + 32993536 = 4269^2 + 5744^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51217897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51217891) 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 3 ways as a sum of consecutive naturals, for example, 624568 + ... + 624649.

It is an arithmetic number, because the mean of its divisors is an integer number (13116789).

Almost surely, 2^51217897 is an apocalyptic number.

It is an amenable number.

51217897 is a deficient number, since it is larger than the sum of its proper divisors (1249259).

51217897 is a wasteful number, since it uses less digits than its factorization.

51217897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1249258.

The product of its digits is 35280, while the sum is 40.

The square root of 51217897 is about 7156.6680096257. The cubic root of 51217897 is about 371.3703675422.

The spelling of 51217897 in words is "fifty-one million, two hundred seventeen thousand, eight hundred ninety-seven".