51085221 has 32 divisors (see below), whose sum is σ = 80631936. Its totient is φ = 28416000.

The previous prime is 51085213. The next prime is 51085249. The reversal of 51085221 is 12258015.

It is not a de Polignac number, because 51085221 - 2³ = 51085213 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 51085191 and 51085200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51085201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21891 + ... + 24111.

It is an arithmetic number, because the mean of its divisors is an integer number (2519748).

Almost surely, 2^51085221 is an apocalyptic number.

51085221 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

51085221 is a deficient number, since it is larger than the sum of its proper divisors (29546715).

51085221 is a wasteful number, since it uses less digits than its factorization.

51085221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2293.

The product of its (nonzero) digits is 800, while the sum is 24.

The square root of 51085221 is about 7147.3926015016. The cubic root of 51085221 is about 371.0494215178.

The spelling of 51085221 in words is "fifty-one million, eighty-five thousand, two hundred twenty-one".