51621222 has 16 divisors (see below), whose sum is σ = 104784192. Its totient is φ = 16950120.

The previous prime is 51621217. The next prime is 51621239. The reversal of 51621222 is 22212615.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63804 + ... + 64607.

It is an arithmetic number, because the mean of its divisors is an integer number (6549012).

Almost surely, 2^51621222 is an apocalyptic number.

51621222 is an abundant number, since it is smaller than the sum of its proper divisors (53162970).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51621222 is a wasteful number, since it uses less digits than its factorization.

51621222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128483.

The product of its digits is 480, while the sum is 21.

The square root of 51621222 is about 7184.7910199254. The cubic root of 51621222 is about 372.3426285979.

Adding to 51621222 its reverse (22212615), we get a palindrome (73833837).

The spelling of 51621222 in words is "fifty-one million, six hundred twenty-one thousand, two hundred twenty-two".