51235640 has 32 divisors (see below), whose sum is σ = 117737280. Its totient is φ = 20057472.

The previous prime is 51235631. The next prime is 51235649. The reversal of 51235640 is 4653215.

51235640 = 1021² + 1022² + ... + 1067².

51235640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (51235631) and next prime (51235649).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51235649) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 11747 + ... + 15506.

It is an arithmetic number, because the mean of its divisors is an integer number (3679290).

Almost surely, 2^51235640 is an apocalyptic number.

It is an amenable number.

51235640 is an abundant number, since it is smaller than the sum of its proper divisors (66501640).

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

51235640 is a wasteful number, since it uses less digits than its factorization.

51235640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27311 (or 27307 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 51235640 is about 7157.9075154685. The cubic root of 51235640 is about 371.4132461978.

Adding to 51235640 its reverse (4653215), we get a palindrome (55888855).

The spelling of 51235640 in words is "fifty-one million, two hundred thirty-five thousand, six hundred forty".