51208215520 has 192 divisors, whose sum is σ = 155698163712. Its totient is φ = 15446016000.

The previous prime is 51208215511. The next prime is 51208215581. The reversal of 51208215520 is 2551280215.

It is a Harshad number since it is a multiple of its sum of digits (31).

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, 314880 + ... + 448960.

It is an arithmetic number, because the mean of its divisors is an integer number (810927936).

Almost surely, 2^51208215520 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 51208215520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77849081856).

51208215520 is an abundant number, since it is smaller than the sum of its proper divisors (104489948192).

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

51208215520 is a wasteful number, since it uses less digits than its factorization.

51208215520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134145 (or 134137 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 31.

Adding to 51208215520 its reverse (2551280215), we get a palindrome (53759495735).

The spelling of 51208215520 in words is "fifty-one billion, two hundred eight million, two hundred fifteen thousand, five hundred twenty".