51220055424 has 64 divisors (see below), whose sum is σ = 136209302640. Its totient is φ = 17053771776.

The previous prime is 51220055417. The next prime is 51220055431. The reversal of 51220055424 is 42455002215.

It is an interprime number because it is at equal distance from previous prime (51220055417) and next prime (51220055431).

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 51220055391 and 51220055400.

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, 260722 + ... + 412814.

Almost surely, 2^51220055424 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 51220055424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68104651320).

51220055424 is an abundant number, since it is smaller than the sum of its proper divisors (84989247216).

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

51220055424 is a wasteful number, since it uses less digits than its factorization.

51220055424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152987 (or 152975 counting only the distinct ones).

The product of its (nonzero) digits is 16000, while the sum is 30.

Adding to 51220055424 its reverse (42455002215), we get a palindrome (93675057639).

The spelling of 51220055424 in words is "fifty-one billion, two hundred twenty million, fifty-five thousand, four hundred twenty-four".