51213140 has 48 divisors (see below), whose sum is σ = 118286784. Its totient is φ = 18470400.

The previous prime is 51213139. The next prime is 51213179. The reversal of 51213140 is 4131215.

51213140 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27932 + ... + 29708.

It is an arithmetic number, because the mean of its divisors is an integer number (2464308).

Almost surely, 2^51213140 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 51213140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59143392).

51213140 is an abundant number, since it is smaller than the sum of its proper divisors (67073644).

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

51213140 is a wasteful number, since it uses less digits than its factorization.

51213140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1928 (or 1926 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 51213140 is about 7156.3356545092. The cubic root of 51213140 is about 371.3588698455.

Adding to 51213140 its reverse (4131215), we get a palindrome (55344355).

The spelling of 51213140 in words is "fifty-one million, two hundred thirteen thousand, one hundred forty".