51231132 has 72 divisors (see below), whose sum is σ = 138692736. Its totient is φ = 15888384.

The previous prime is 51231121. The next prime is 51231133. The reversal of 51231132 is 23113215.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51231133) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 58933 + ... + 59795.

It is an arithmetic number, because the mean of its divisors is an integer number (1926288).

Almost surely, 2^51231132 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 51231132, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69346368).

51231132 is an abundant number, since it is smaller than the sum of its proper divisors (87461604).

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

51231132 is a wasteful number, since it uses less digits than its factorization.

51231132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 987 (or 982 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 51231132 is about 7157.5926120449. The cubic root of 51231132 is about 371.4023528690.

Adding to 51231132 its reverse (23113215), we get a palindrome (74344347).

The spelling of 51231132 in words is "fifty-one million, two hundred thirty-one thousand, one hundred thirty-two".