51220116 has 72 divisors (see below), whose sum is σ = 138378240. Its totient is φ = 15918336.

The previous prime is 51220109. The next prime is 51220129. The reversal of 51220116 is 61102215.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 77395 + ... + 78053.

It is an arithmetic number, because the mean of its divisors is an integer number (1921920).

Almost surely, 2^51220116 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51220116, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69189120).

51220116 is an abundant number, since it is smaller than the sum of its proper divisors (87158124).

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

51220116 is a wasteful number, since it uses less digits than its factorization.

51220116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 813 (or 808 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 51220116 is about 7156.8230381923. The cubic root of 51220116 is about 371.3757306346.

The spelling of 51220116 in words is "fifty-one million, two hundred twenty thousand, one hundred sixteen".