51081408 has 224 divisors, whose sum is σ = 177515520. Its totient is φ = 14100480.

The previous prime is 51081389. The next prime is 51081467. The reversal of 51081408 is 80418015.

51081408 is a `hidden beast` number, since 510 + 8 + 140 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 495885 + ... + 495987.

It is an arithmetic number, because the mean of its divisors is an integer number (792480).

Almost surely, 2^51081408 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 51081408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88757760).

51081408 is an abundant number, since it is smaller than the sum of its proper divisors (126434112).

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

51081408 is a wasteful number, since it uses less digits than its factorization.

51081408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 156 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 51081408 is about 7147.1258558948. The cubic root of 51081408 is about 371.0401895807.

It can be divided in two parts, 510 and 81408, that added together give a palindrome (81918).

The spelling of 51081408 in words is "fifty-one million, eighty-one thousand, four hundred eight".