51213004220 has 96 divisors (see below), whose sum is σ = 130796467200. Its totient is φ = 16442680320.

The previous prime is 51213004097. The next prime is 51213004231. The reversal of 51213004220 is 2240031215.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 51213004192 and 51213004201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 419555 + ... + 527685.

It is an arithmetic number, because the mean of its divisors is an integer number (1362463200).

Almost surely, 2^51213004220 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 51213004220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65398233600).

51213004220 is an abundant number, since it is smaller than the sum of its proper divisors (79583462980).

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

51213004220 is a wasteful number, since it uses less digits than its factorization.

51213004220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108363 (or 108361 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

Adding to 51213004220 its reverse (2240031215), we get a palindrome (53453035435).

The spelling of 51213004220 in words is "fifty-one billion, two hundred thirteen million, four thousand, two hundred twenty".