51026721 has 4 divisors (see below), whose sum is σ = 68035632. Its totient is φ = 34017812.

The previous prime is 51026687. The next prime is 51026791. The reversal of 51026721 is 12762015.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51026721 - 2⁷ = 51026593 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51026691 and 51026700.

It is not an unprimeable number, because it can be changed into a prime (51026791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8504451 + ... + 8504456.

It is an arithmetic number, because the mean of its divisors is an integer number (17008908).

Almost surely, 2^51026721 is an apocalyptic number.

It is an amenable number.

51026721 is a deficient number, since it is larger than the sum of its proper divisors (17008911).

51026721 is a wasteful number, since it uses less digits than its factorization.

51026721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17008910.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 51026721 is about 7143.2990277602. The cubic root of 51026721 is about 370.9077322538.

Adding to 51026721 its reverse (12762015), we get a palindrome (63788736).

The spelling of 51026721 in words is "fifty-one million, twenty-six thousand, seven hundred twenty-one".