51489984 has 168 divisors, whose sum is σ = 171072048. Its totient is φ = 13547520.

The previous prime is 51489983. The next prime is 51490001. The reversal of 51489984 is 48998415.

It is a tau number, because it is divible by the number of its divisors (168).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51489983) 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, 122094 + ... + 122514.

It is an arithmetic number, because the mean of its divisors is an integer number (1018286).

Almost surely, 2^51489984 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 51489984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85536024).

51489984 is an abundant number, since it is smaller than the sum of its proper divisors (119582064).

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

51489984 is a wasteful number, since it uses less digits than its factorization.

51489984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463 (or 446 counting only the distinct ones).

The product of its digits is 414720, while the sum is 48.

The square root of 51489984 is about 7175.6521654829. The cubic root of 51489984 is about 372.0268219763.

The spelling of 51489984 in words is "fifty-one million, four hundred eighty-nine thousand, nine hundred eighty-four".