51842640 has 80 divisors (see below), whose sum is σ = 169185600. Its totient is φ = 13095936.

The previous prime is 51842627. The next prime is 51842641. The reversal of 51842640 is 4624815.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 51842598 and 51842607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51842641) 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 15 ways as a sum of consecutive naturals, for example, 1125 + ... + 10244.

It is an arithmetic number, because the mean of its divisors is an integer number (2114820).

Almost surely, 2^51842640 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 51842640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84592800).

51842640 is an abundant number, since it is smaller than the sum of its proper divisors (117342960).

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

51842640 is a wasteful number, since it uses less digits than its factorization.

51842640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11404 (or 11398 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 51842640 is about 7200.1833309993. The cubic root of 51842640 is about 372.8742301547.

The spelling of 51842640 in words is "fifty-one million, eight hundred forty-two thousand, six hundred forty".