51939216 has 180 divisors, whose sum is σ = 179449452. Its totient is φ = 13934592.

The previous prime is 51939187. The next prime is 51939259. The reversal of 51939216 is 61293915.

It can be written as a sum of positive squares in 2 ways, for example, as 22127616 + 29811600 = 4704^2 + 5460^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 119736 + ... + 120168.

Almost surely, 2^51939216 is an apocalyptic number.

51939216 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51939216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89724726).

51939216 is an abundant number, since it is smaller than the sum of its proper divisors (127510236).

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

51939216 is a wasteful number, since it uses less digits than its factorization.

51939216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 462 counting only the distinct ones).

The product of its digits is 14580, while the sum is 36.

The square root of 51939216 is about 7206.8867064774. The cubic root of 51939216 is about 373.1056250303.

The spelling of 51939216 in words is "fifty-one million, nine hundred thirty-nine thousand, two hundred sixteen".