51549440 has 144 divisors (see below), whose sum is σ = 137749248. Its totient is φ = 18382848.

The previous prime is 51549439. The next prime is 51549493. The reversal of 51549440 is 4494515.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 51549397 and 51549406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 500429 + ... + 500531.

It is an arithmetic number, because the mean of its divisors is an integer number (956592).

Almost surely, 2^51549440 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 51549440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68874624).

51549440 is an abundant number, since it is smaller than the sum of its proper divisors (86199808).

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

51549440 is a wasteful number, since it uses less digits than its factorization.

51549440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 51549440 is about 7179.7938689074. The cubic root of 51549440 is about 372.1699612609.

The spelling of 51549440 in words is "fifty-one million, five hundred forty-nine thousand, four hundred forty".