51002140 has 72 divisors (see below), whose sum is σ = 126518112. Its totient is φ = 17216640.

The previous prime is 51002129. The next prime is 51002141. The reversal of 51002140 is 4120015.

It is a self number, because there is not a number n which added to its sum of digits gives 51002140.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51002141) 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, 69214 + ... + 69946.

It is an arithmetic number, because the mean of its divisors is an integer number (1757196).

Almost surely, 2^51002140 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 51002140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63259056).

51002140 is an abundant number, since it is smaller than the sum of its proper divisors (75515972).

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

51002140 is a wasteful number, since it uses less digits than its factorization.

51002140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 827 (or 818 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 51002140 is about 7141.5782569401. The cubic root of 51002140 is about 370.8481638081.

Adding to 51002140 its reverse (4120015), we get a palindrome (55122155).

The spelling of 51002140 in words is "fifty-one million, two thousand, one hundred forty".