51221371 has 4 divisors (see below), whose sum is σ = 51504544. Its totient is φ = 50938200.

The previous prime is 51221363. The next prime is 51221413. The reversal of 51221371 is 17312215.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51221371 - 2³ = 51221363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51221771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141315 + ... + 141676.

It is an arithmetic number, because the mean of its divisors is an integer number (12876136).

Almost surely, 2^51221371 is an apocalyptic number.

51221371 is a deficient number, since it is larger than the sum of its proper divisors (283173).

51221371 is a wasteful number, since it uses less digits than its factorization.

51221371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283172.

The product of its digits is 420, while the sum is 22.

The square root of 51221371 is about 7156.9107162239. The cubic root of 51221371 is about 371.3787637706.

Adding to 51221371 its reverse (17312215), we get a palindrome (68533586).

The spelling of 51221371 in words is "fifty-one million, two hundred twenty-one thousand, three hundred seventy-one".