51331340 has 12 divisors (see below), whose sum is σ = 107795856. Its totient is φ = 20532528.

The previous prime is 51331327. The next prime is 51331351. The reversal of 51331340 is 4313315.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 2566567 = 51331340 / (5 + 1 + 3 + 3 + 1 + 3 + 4 + 0).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1283264 + ... + 1283303.

It is an arithmetic number, because the mean of its divisors is an integer number (8982988).

Almost surely, 2^51331340 is an apocalyptic number.

It is an amenable number.

51331340 is an abundant number, since it is smaller than the sum of its proper divisors (56464516).

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

51331340 is a wasteful number, since it uses less digits than its factorization.

51331340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2566576 (or 2566574 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 20.

The square root of 51331340 is about 7164.5893113283. The cubic root of 51331340 is about 371.6443492624.

Adding to 51331340 its reverse (4313315), we get a palindrome (55644655).

The spelling of 51331340 in words is "fifty-one million, three hundred thirty-one thousand, three hundred forty".