51994221 has 8 divisors (see below), whose sum is σ = 69629280. Its totient is φ = 34510992.

The previous prime is 51994193. The next prime is 51994247. The reversal of 51994221 is 12249915.

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

It is not a de Polignac number, because 51994221 - 2⁶ = 51994157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51994121) 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, 37155 + ... + 38528.

It is an arithmetic number, because the mean of its divisors is an integer number (8703660).

Almost surely, 2^51994221 is an apocalyptic number.

It is an amenable number.

51994221 is a deficient number, since it is larger than the sum of its proper divisors (17635059).

51994221 is a wasteful number, since it uses less digits than its factorization.

51994221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75915.

The product of its digits is 6480, while the sum is 33.

The square root of 51994221 is about 7210.7018382402. The cubic root of 51994221 is about 373.2372881297.

The spelling of 51994221 in words is "fifty-one million, nine hundred ninety-four thousand, two hundred twenty-one".