51017221 has 16 divisors (see below), whose sum is σ = 55902528. Its totient is φ = 46368000.

The previous prime is 51017189. The next prime is 51017233. The reversal of 51017221 is 12271015.

It is a cyclic number.

It is not a de Polignac number, because 51017221 - 2⁵ = 51017189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51017251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73486 + ... + 74176.

It is an arithmetic number, because the mean of its divisors is an integer number (3493908).

Almost surely, 2^51017221 is an apocalyptic number.

It is an amenable number.

51017221 is a deficient number, since it is larger than the sum of its proper divisors (4885307).

51017221 is a wasteful number, since it uses less digits than its factorization.

51017221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852.

The product of its (nonzero) digits is 140, while the sum is 19.

The square root of 51017221 is about 7142.6340379443. The cubic root of 51017221 is about 370.8847126667.

Adding to 51017221 its reverse (12271015), we get a palindrome (63288236).

The spelling of 51017221 in words is "fifty-one million, seventeen thousand, two hundred twenty-one".