51333440 has 56 divisors (see below), whose sum is σ = 128686560. Its totient is φ = 19450368.

The previous prime is 51333431. The next prime is 51333461. The reversal of 51333440 is 4433315.

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, 1859 + ... + 10301.

Almost surely, 2^51333440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51333440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64343280).

51333440 is an abundant number, since it is smaller than the sum of its proper divisors (77353120).

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

51333440 is a wasteful number, since it uses less digits than its factorization.

51333440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8479 (or 8469 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 23.

The square root of 51333440 is about 7164.7358639380. The cubic root of 51333440 is about 371.6494172676.

Adding to 51333440 its reverse (4433315), we get a palindrome (55766755).

The spelling of 51333440 in words is "fifty-one million, three hundred thirty-three thousand, four hundred forty".