51451311332520 has 384 divisors, whose sum is σ = 190523940048000. Its totient is φ = 11930240010240.

The previous prime is 51451311332471. The next prime is 51451311332537. The reversal of 51451311332520 is 2523311315415.

It is a happy number.

51451311332520 is a `hidden beast` number, since 5 + 1 + 4 + 5 + 1 + 311 + 332 + 5 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5668786 + ... + 11620574.

It is an arithmetic number, because the mean of its divisors is an integer number (496156093875).

Almost surely, 2^{51451311332520} 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 51451311332520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95261970024000).

51451311332520 is an abundant number, since it is smaller than the sum of its proper divisors (139072628715480).

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

51451311332520 is a wasteful number, since it uses less digits than its factorization.

51451311332520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5951913 (or 5951906 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

Adding to 51451311332520 its reverse (2523311315415), we get a palindrome (53974622647935).

The spelling of 51451311332520 in words is "fifty-one trillion, four hundred fifty-one billion, three hundred eleven million, three hundred thirty-two thousand, five hundred twenty".