51447221 has 8 divisors (see below), whose sum is σ = 60164544. Its totient is φ = 43071840.

The previous prime is 51447211. The next prime is 51447257. The reversal of 51447221 is 12274415.

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

It is not a de Polignac number, because 51447221 - 2⁶ = 51447157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51447211) 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 7 ways as a sum of consecutive naturals, for example, 85160 + ... + 85761.

It is an arithmetic number, because the mean of its divisors is an integer number (7520568).

Almost surely, 2^51447221 is an apocalyptic number.

It is an amenable number.

51447221 is a deficient number, since it is larger than the sum of its proper divisors (8717323).

51447221 is a wasteful number, since it uses less digits than its factorization.

51447221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170971.

The product of its digits is 2240, while the sum is 26.

The square root of 51447221 is about 7172.6718173913. The cubic root of 51447221 is about 371.9238026576.

The spelling of 51447221 in words is "fifty-one million, four hundred forty-seven thousand, two hundred twenty-one".