51132720 has 80 divisors (see below), whose sum is σ = 159320160. Its totient is φ = 13565952.

The previous prime is 51132707. The next prime is 51132721. The reversal of 51132720 is 2723115.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×51132720² = 5229110109196800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51132721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61266 + ... + 62094.

It is an arithmetic number, because the mean of its divisors is an integer number (1991502).

Almost surely, 2^51132720 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 51132720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79660080).

51132720 is an abundant number, since it is smaller than the sum of its proper divisors (108187440).

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

51132720 is a wasteful number, since it uses less digits than its factorization.

51132720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1102 (or 1096 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 51132720 is about 7150.7146495997. The cubic root of 51132720 is about 371.1643863846.

Adding to 51132720 its reverse (2723115), we get a palindrome (53855835).

The spelling of 51132720 in words is "fifty-one million, one hundred thirty-two thousand, seven hundred twenty".