51909888 has 72 divisors (see below), whose sum is σ = 139220928. Its totient is φ = 17170432.

The previous prime is 51909887. The next prime is 51909917. The reversal of 51909888 is 88890915.

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 (51909883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 197245 + ... + 197507.

It is an arithmetic number, because the mean of its divisors is an integer number (1933624).

Almost surely, 2^51909888 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 51909888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69610464).

51909888 is an abundant number, since it is smaller than the sum of its proper divisors (87311040).

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

51909888 is a wasteful number, since it uses less digits than its factorization.

51909888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539 (or 525 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 48.

The square root of 51909888 is about 7204.8516986819. The cubic root of 51909888 is about 373.0353858620.

The spelling of 51909888 in words is "fifty-one million, nine hundred nine thousand, eight hundred eighty-eight".