51240000 has 280 divisors, whose sum is σ = 196787008. Its totient is φ = 11520000.

The previous prime is 51239983. The next prime is 51240001. The reversal of 51240000 is 4215.

It is a tau number, because it is divible by the number of its divisors (280).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (51240001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 839970 + ... + 840030.

Almost surely, 2^51240000 is an apocalyptic number.

51240000 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 51240000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98393504).

51240000 is an abundant number, since it is smaller than the sum of its proper divisors (145547008).

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

51240000 is an equidigital number, since it uses as much as digits as its factorization.

51240000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 51240000 is about 7158.2120672693. The cubic root of 51240000 is about 371.4237812851.

Adding to 51240000 its reverse (4215), we get a palindrome (51244215).

The spelling of 51240000 in words is "fifty-one million, two hundred forty thousand".