51087972 has 96 divisors (see below), whose sum is σ = 135136512. Its totient is φ = 14916096.

The previous prime is 51087947. The next prime is 51087977. The reversal of 51087972 is 27978015.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 51087972.

It is not an unprimeable number, because it can be changed into a prime (51087977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 305833 + ... + 305999.

It is an arithmetic number, because the mean of its divisors is an integer number (1407672).

Almost surely, 2^51087972 is an apocalyptic number.

51087972 is a gapful number since it is divisible by the number (52) 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 51087972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67568256).

51087972 is an abundant number, since it is smaller than the sum of its proper divisors (84048540).

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

51087972 is a wasteful number, since it uses less digits than its factorization.

51087972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277 (or 275 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 39.

The square root of 51087972 is about 7147.5850467133. The cubic root of 51087972 is about 371.0560818827.

The spelling of 51087972 in words is "fifty-one million, eighty-seven thousand, nine hundred seventy-two".