51312340 has 24 divisors (see below), whose sum is σ = 110669832. Its totient is φ = 19969920.

The previous prime is 51312337. The next prime is 51312353. The reversal of 51312340 is 4321315.

It can be written as a sum of positive squares in 4 ways, for example, as 8749764 + 42562576 = 2958^2 + 6524^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33931 + ... + 35410.

It is an arithmetic number, because the mean of its divisors is an integer number (4611243).

Almost surely, 2^51312340 is an apocalyptic number.

It is an amenable number.

51312340 is an abundant number, since it is smaller than the sum of its proper divisors (59357492).

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

51312340 is a wasteful number, since it uses less digits than its factorization.

51312340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69387 (or 69385 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 51312340 is about 7163.2632228615. The cubic root of 51312340 is about 371.5984895983.

Adding to 51312340 its reverse (4321315), we get a palindrome (55633655).

Subtracting from 51312340 its reverse (4321315), we obtain a square (46991025 = 6855²).

The spelling of 51312340 in words is "fifty-one million, three hundred twelve thousand, three hundred forty".