51310021 has 8 divisors (see below), whose sum is σ = 59443904. Its totient is φ = 43377120.

The previous prime is 51310003. The next prime is 51310027. The reversal of 51310021 is 12001315.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51310021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51309983 and 51310010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51310027) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49695 + ... + 50716.

It is an arithmetic number, because the mean of its divisors is an integer number (7430488).

Almost surely, 2^51310021 is an apocalyptic number.

It is an amenable number.

51310021 is a deficient number, since it is larger than the sum of its proper divisors (8133883).

51310021 is a wasteful number, since it uses less digits than its factorization.

51310021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100491.

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 51310021 is about 7163.1013534642. The cubic root of 51310021 is about 371.5928915304.

Adding to 51310021 its reverse (12001315), we get a palindrome (63311336).

The spelling of 51310021 in words is "fifty-one million, three hundred ten thousand, twenty-one".