51115534380 has 240 divisors, whose sum is σ = 172572767136. Its totient is φ = 12618270720.

The previous prime is 51115534361. The next prime is 51115534381. The reversal of 51115534380 is 8343551115.

It is a happy number.

51115534380 is a `hidden beast` number, since 5 + 1 + 115 + 534 + 3 + 8 + 0 = 666.

51115534380 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×51115534380² (a number of 22 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (51115534381) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1664727 + ... + 1695153.

Almost surely, 2^51115534380 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 51115534380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86286383568).

51115534380 is an abundant number, since it is smaller than the sum of its proper divisors (121457232756).

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

51115534380 is a wasteful number, since it uses less digits than its factorization.

51115534380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30526 (or 30515 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 36.

The spelling of 51115534380 in words is "fifty-one billion, one hundred fifteen million, five hundred thirty-four thousand, three hundred eighty".