51223216 has 20 divisors (see below), whose sum is σ = 108267624. Its totient is φ = 23283200.

The previous prime is 51223213. The next prime is 51223217. The reversal of 51223216 is 61232215.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51223213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 145345 + ... + 145696.

Almost surely, 2^51223216 is an apocalyptic number.

It is an amenable number.

51223216 is an abundant number, since it is smaller than the sum of its proper divisors (57044408).

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

51223216 is a wasteful number, since it uses less digits than its factorization.

51223216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291060 (or 291054 counting only the distinct ones).

The product of its digits is 720, while the sum is 22.

The square root of 51223216 is about 7157.0396114595. The cubic root of 51223216 is about 371.3832227531.

It can be divided in two parts, 5122 and 3216, that added together give a palindrome (8338).

The spelling of 51223216 in words is "fifty-one million, two hundred twenty-three thousand, two hundred sixteen".