51030021 has 12 divisors (see below), whose sum is σ = 79148832. Its totient is φ = 29159928.

The previous prime is 51030017. The next prime is 51030037. The reversal of 51030021 is 12003015.

It is not a de Polignac number, because 51030021 - 2² = 51030017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51029979 and 51030006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51030041) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 173425 + ... + 173718.

It is an arithmetic number, because the mean of its divisors is an integer number (6595736).

Almost surely, 2^51030021 is an apocalyptic number.

It is an amenable number.

51030021 is a deficient number, since it is larger than the sum of its proper divisors (28118811).

51030021 is a wasteful number, since it uses less digits than its factorization.

51030021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347160 (or 347153 counting only the distinct ones).

The product of its (nonzero) digits is 30, while the sum is 12.

The square root of 51030021 is about 7143.5300097361. The cubic root of 51030021 is about 370.9157278628.

Adding to 51030021 its reverse (12003015), we get a palindrome (63033036).

The spelling of 51030021 in words is "fifty-one million, thirty thousand, twenty-one".