51587640 has 192 divisors, whose sum is σ = 184242240. Its totient is φ = 12441600.

The previous prime is 51587633. The next prime is 51587663. The reversal of 51587640 is 4678515.

51587640 is a `hidden beast` number, since 5 + 1 + 5 + 8 + 7 + 640 = 666.

It is a super-2 number, since 2×51587640² = 5322569201539200, which contains 22 as substring.

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 = 51587595 and 51587604.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 341565 + ... + 341715.

It is an arithmetic number, because the mean of its divisors is an integer number (959595).

Almost surely, 2^51587640 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 51587640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92121120).

51587640 is an abundant number, since it is smaller than the sum of its proper divisors (132654600).

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

51587640 is a wasteful number, since it uses less digits than its factorization.

51587640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 51587640 is about 7182.4536197598. The cubic root of 51587640 is about 372.2618690309.

The spelling of 51587640 in words is "fifty-one million, five hundred eighty-seven thousand, six hundred forty".