51221761123464 has 128 divisors (see below), whose sum is σ = 144650098944000. Its totient is φ = 16789964083200.

The previous prime is 51221761123457. The next prime is 51221761123487. The reversal of 51221761123464 is 46432116712215.

It is a happy number.

51221761123464 is a `hidden beast` number, since 5 + 1 + 2 + 2 + 1 + 7 + 61 + 123 + 464 = 666.

51221761123464 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54331624 + ... + 55266344.

It is an arithmetic number, because the mean of its divisors is an integer number (1130078898000).

Almost surely, 2^{51221761123464} is an apocalyptic number.

51221761123464 is a gapful number since it is divisible by the number (54) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51221761123464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72325049472000).

51221761123464 is an abundant number, since it is smaller than the sum of its proper divisors (93428337820536).

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

51221761123464 is a wasteful number, since it uses less digits than its factorization.

51221761123464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 938956 (or 938946 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

Adding to 51221761123464 its reverse (46432116712215), we get a palindrome (97653877835679).

The spelling of 51221761123464 in words is "fifty-one trillion, two hundred twenty-one billion, seven hundred sixty-one million, one hundred twenty-three thousand, four hundred sixty-four".