51505650 has 144 divisors (see below), whose sum is σ = 160864704. Its totient is φ = 11571840.

The previous prime is 51505621. The next prime is 51505669. The reversal of 51505650 is 5650515.

51505650 is a `hidden beast` number, since 5 + 1 + 5 + 0 + 5 + 650 = 666.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 261352 + ... + 261548.

It is an arithmetic number, because the mean of its divisors is an integer number (1117116).

Almost surely, 2^51505650 is an apocalyptic number.

51505650 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 51505650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80432352).

51505650 is an abundant number, since it is smaller than the sum of its proper divisors (109359054).

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

51505650 is a wasteful number, since it uses less digits than its factorization.

51505650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305 (or 297 counting only the distinct ones).

The product of its (nonzero) digits is 3750, while the sum is 27.

The square root of 51505650 is about 7176.7436905605. The cubic root of 51505650 is about 372.0645482858.

The spelling of 51505650 in words is "fifty-one million, five hundred five thousand, six hundred fifty".