51453440 has 80 divisors (see below), whose sum is σ = 125215200. Its totient is φ = 20275200.

The previous prime is 51453433. The next prime is 51453449. The reversal of 51453440 is 4435415.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51453449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 258461 + ... + 258659.

It is an arithmetic number, because the mean of its divisors is an integer number (1565190).

Almost surely, 2^51453440 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 51453440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62607600).

51453440 is an abundant number, since it is smaller than the sum of its proper divisors (73761760).

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

51453440 is a wasteful number, since it uses less digits than its factorization.

51453440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 307 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 26.

The square root of 51453440 is about 7173.1053247530. The cubic root of 51453440 is about 371.9387882479.

Adding to 51453440 its reverse (4435415), we get a palindrome (55888855).

The spelling of 51453440 in words is "fifty-one million, four hundred fifty-three thousand, four hundred forty".