51332240 has 40 divisors (see below), whose sum is σ = 120548088. Its totient is φ = 20326400.

The previous prime is 51332227. The next prime is 51332269. The reversal of 51332240 is 4223315.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 16096144 + 35236096 = 4012^2 + 5936^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 4904 + ... + 11256.

Almost surely, 2^51332240 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 51332240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60274044).

51332240 is an abundant number, since it is smaller than the sum of its proper divisors (69215848).

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

51332240 is a wasteful number, since it uses less digits than its factorization.

51332240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6467 (or 6461 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 51332240 is about 7164.6521199567. The cubic root of 51332240 is about 371.6465212816.

Adding to 51332240 its reverse (4223315), we get a palindrome (55555555).

The spelling of 51332240 in words is "fifty-one million, three hundred thirty-two thousand, two hundred forty".