51505384 has 32 divisors (see below), whose sum is σ = 113932800. Its totient is φ = 21360960.

The previous prime is 51505381. The next prime is 51505397. The reversal of 51505384 is 48350515.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is not an unprimeable number, because it can be changed into a prime (51505381) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13099 + ... + 16570.

It is an arithmetic number, because the mean of its divisors is an integer number (3560400).

Almost surely, 2^51505384 is an apocalyptic number.

It is an amenable number.

51505384 is an abundant number, since it is smaller than the sum of its proper divisors (62427416).

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

51505384 is a wasteful number, since it uses less digits than its factorization.

51505384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29713 (or 29709 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 31.

The square root of 51505384 is about 7176.7251584549. The cubic root of 51505384 is about 372.0639077778.

Adding to 51505384 its reverse (48350515), we get a palindrome (99855899).

The spelling of 51505384 in words is "fifty-one million, five hundred five thousand, three hundred eighty-four".