51055221 has 8 divisors (see below), whose sum is σ = 77798464. Its totient is φ = 29174400.

The previous prime is 51055217. The next prime is 51055229. The reversal of 51055221 is 12255015.

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

It is not a de Polignac number, because 51055221 - 2² = 51055217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 2431201 = 51055221 / (5 + 1 + 0 + 5 + 5 + 2 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51055229) 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, 1215580 + ... + 1215621.

It is an arithmetic number, because the mean of its divisors is an integer number (9724808).

Almost surely, 2^51055221 is an apocalyptic number.

It is an amenable number.

51055221 is a deficient number, since it is larger than the sum of its proper divisors (26743243).

51055221 is a wasteful number, since it uses less digits than its factorization.

51055221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2431211.

The product of its (nonzero) digits is 500, while the sum is 21.

The square root of 51055221 is about 7145.2936258771. The cubic root of 51055221 is about 370.9767738770.

The spelling of 51055221 in words is "fifty-one million, fifty-five thousand, two hundred twenty-one".