51304140 has 36 divisors (see below), whose sum is σ = 155623104. Its totient is φ = 13681056.

The previous prime is 51304133. The next prime is 51304151. The reversal of 51304140 is 4140315.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×51304140² = 5264229562279200, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 142332 + ... + 142691.

It is an arithmetic number, because the mean of its divisors is an integer number (4322864).

Almost surely, 2^51304140 is an apocalyptic number.

It is an amenable number.

51304140 is an abundant number, since it is smaller than the sum of its proper divisors (104318964).

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

51304140 is a wasteful number, since it uses less digits than its factorization.

51304140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285038 (or 285033 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 51304140 is about 7162.6908351541. The cubic root of 51304140 is about 371.5786940355.

Adding to 51304140 its reverse (4140315), we get a palindrome (55444455).

The spelling of 51304140 in words is "fifty-one million, three hundred four thousand, one hundred forty".