51489540 has 96 divisors (see below), whose sum is σ = 162005760. Its totient is φ = 13575168.

The previous prime is 51489539. The next prime is 51489623. The reversal of 51489540 is 4598415.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 51489495 and 51489504.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 51889 + ... + 52871.

It is an arithmetic number, because the mean of its divisors is an integer number (1687560).

Almost surely, 2^51489540 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 51489540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81002880).

51489540 is an abundant number, since it is smaller than the sum of its proper divisors (110516220).

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

51489540 is a wasteful number, since it uses less digits than its factorization.

51489540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1098 (or 1090 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 51489540 is about 7175.6212274618. The cubic root of 51489540 is about 372.0257526396.

The spelling of 51489540 in words is "fifty-one million, four hundred eighty-nine thousand, five hundred forty".