51504440 has 96 divisors (see below), whose sum is σ = 132418800. Its totient is φ = 17971200.

The previous prime is 51504437. The next prime is 51504443. The reversal of 51504440 is 4440515.

51504440 = T₁₅₉ + T₁₆₀ + ... + T₆₇₈.

It is an interprime number because it is at equal distance from previous prime (51504437) and next prime (51504443).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51504443) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 128240 + ... + 128640.

Almost surely, 2^51504440 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 51504440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66209400).

51504440 is an abundant number, since it is smaller than the sum of its proper divisors (80914360).

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

51504440 is a wasteful number, since it uses less digits than its factorization.

51504440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457 (or 440 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 51504440 is about 7176.6593899948. The cubic root of 51504440 is about 372.0616346790.

Adding to 51504440 its reverse (4440515), we get a palindrome (55944955).

The spelling of 51504440 in words is "fifty-one million, five hundred four thousand, four hundred forty".