51165561552 has 160 divisors (see below), whose sum is σ = 154774093824. Its totient is φ = 14263603200.

The previous prime is 51165561547. The next prime is 51165561553. The reversal of 51165561552 is 25516556115.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51165561553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2302977 + ... + 2325087.

Almost surely, 2^51165561552 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 51165561552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77387046912).

51165561552 is an abundant number, since it is smaller than the sum of its proper divisors (103608532272).

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

51165561552 is a wasteful number, since it uses less digits than its factorization.

51165561552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22297 (or 22291 counting only the distinct ones).

The product of its digits is 225000, while the sum is 42.

The spelling of 51165561552 in words is "fifty-one billion, one hundred sixty-five million, five hundred sixty-one thousand, five hundred fifty-two".