51611440 has 40 divisors (see below), whose sum is σ = 121800240. Its totient is φ = 20334336.

The previous prime is 51611431. The next prime is 51611449. The reversal of 51611440 is 4411615.

It is an interprime number because it is at equal distance from previous prime (51611431) and next prime (51611449).

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

It is not an unprimeable number, because it can be changed into a prime (51611449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 546 + ... + 10174.

It is an arithmetic number, because the mean of its divisors is an integer number (3045006).

Almost surely, 2^51611440 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 51611440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60900120).

51611440 is an abundant number, since it is smaller than the sum of its proper divisors (70188800).

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

51611440 is a wasteful number, since it uses less digits than its factorization.

51611440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9709 (or 9703 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 51611440 is about 7184.1102441430. The cubic root of 51611440 is about 372.3191080022.

The spelling of 51611440 in words is "fifty-one million, six hundred eleven thousand, four hundred forty".