51243321220 has 48 divisors (see below), whose sum is σ = 132444281088. Its totient is φ = 16217665920.

The previous prime is 51243321211. The next prime is 51243321277. The reversal of 51243321220 is 2212334215.

It is a super-2 number, since 2×51243321220² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14076016 + ... + 14079655.

It is an arithmetic number, because the mean of its divisors is an integer number (2759255856).

Almost surely, 2^51243321220 is an apocalyptic number.

It is an amenable number.

51243321220 is an abundant number, since it is smaller than the sum of its proper divisors (81200959868).

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

51243321220 is a wasteful number, since it uses less digits than its factorization.

51243321220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28155700 (or 28155698 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 51243321220 its reverse (2212334215), we get a palindrome (53455655435).

The spelling of 51243321220 in words is "fifty-one billion, two hundred forty-three million, three hundred twenty-one thousand, two hundred twenty".