51313500 has 240 divisors, whose sum is σ = 192384192. Its totient is φ = 11664000.

The previous prime is 51313481. The next prime is 51313501. The reversal of 51313500 is 531315.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51313501) 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, 283410 + ... + 283590.

Almost surely, 2^51313500 is an apocalyptic number.

51313500 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51313500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96192096).

51313500 is an abundant number, since it is smaller than the sum of its proper divisors (141070692).

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

51313500 is a wasteful number, since it uses less digits than its factorization.

51313500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219 (or 198 counting only the distinct ones).

The product of its (nonzero) digits is 225, while the sum is 18.

The square root of 51313500 is about 7163.3441910884. The cubic root of 51313500 is about 371.6012897759.

Adding to 51313500 its reverse (531315), we get a palindrome (51844815).

The spelling of 51313500 in words is "fifty-one million, three hundred thirteen thousand, five hundred".