51616221 has 8 divisors (see below), whose sum is σ = 70681824. Its totient is φ = 33480720.

The previous prime is 51616189. The next prime is 51616237. The reversal of 51616221 is 12261615.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51616221 - 2⁵ = 51616189 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 51616191 and 51616200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51616241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 232395 + ... + 232616.

It is an arithmetic number, because the mean of its divisors is an integer number (8835228).

Almost surely, 2^51616221 is an apocalyptic number.

It is an amenable number.

51616221 is a deficient number, since it is larger than the sum of its proper divisors (19065603).

51616221 is a wasteful number, since it uses less digits than its factorization.

51616221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465051.

The product of its digits is 720, while the sum is 24.

The square root of 51616221 is about 7184.4429846718. The cubic root of 51616221 is about 372.3306041788.

Adding to 51616221 its reverse (12261615), we get a palindrome (63877836).

The spelling of 51616221 in words is "fifty-one million, six hundred sixteen thousand, two hundred twenty-one".