51405516 has 60 divisors (see below), whose sum is σ = 139043520. Its totient is φ = 16541280.

The previous prime is 51405509. The next prime is 51405517. The reversal of 51405516 is 61550415.

It is a happy number.

51405516 is a `hidden beast` number, since 5 + 140 + 5 + 516 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 51405516.

It is not an unprimeable number, because it can be changed into a prime (51405517) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6661 + ... + 12131.

It is an arithmetic number, because the mean of its divisors is an integer number (2317392).

Almost surely, 2^51405516 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 51405516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69521760).

51405516 is an abundant number, since it is smaller than the sum of its proper divisors (87638004).

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

51405516 is a wasteful number, since it uses less digits than its factorization.

51405516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5516 (or 5505 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The square root of 51405516 is about 7169.7640128529. The cubic root of 51405516 is about 371.8232771413.

The spelling of 51405516 in words is "fifty-one million, four hundred five thousand, five hundred sixteen".