51709320 has 256 divisors, whose sum is σ = 193536000. Its totient is φ = 12192768.

The previous prime is 51709309. The next prime is 51709367. The reversal of 51709320 is 2390715.

51709320 = 166² + 167² + ... + 542².

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 407097 + ... + 407223.

It is an arithmetic number, because the mean of its divisors is an integer number (756000).

Almost surely, 2^51709320 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 51709320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96768000).

51709320 is an abundant number, since it is smaller than the sum of its proper divisors (141826680).

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

51709320 is a wasteful number, since it uses less digits than its factorization.

51709320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 179 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 51709320 is about 7190.9192736395. The cubic root of 51709320 is about 372.5543244645.

The spelling of 51709320 in words is "fifty-one million, seven hundred nine thousand, three hundred twenty".