51017720 has 48 divisors (see below), whose sum is σ = 124315560. Its totient is φ = 18834816.

The previous prime is 51017711. The next prime is 51017741. The reversal of 51017720 is 2771015.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2987 + ... + 10533.

Almost surely, 2^51017720 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 51017720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62157780).

51017720 is an abundant number, since it is smaller than the sum of its proper divisors (73297840).

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

51017720 is a wasteful number, since it uses less digits than its factorization.

51017720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7584 (or 7567 counting only the distinct ones).

The product of its (nonzero) digits is 490, while the sum is 23.

The square root of 51017720 is about 7142.6689689499. The cubic root of 51017720 is about 370.8859218719.

Adding to 51017720 its reverse (2771015), we get a palindrome (53788735).

It can be divided in two parts, 5101 and 7720, that added together give a palindrome (12821).

The spelling of 51017720 in words is "fifty-one million, seventeen thousand, seven hundred twenty".