51828721 has 12 divisors (see below), whose sum is σ = 61194288. Its totient is φ = 43758792.

The previous prime is 51828719. The next prime is 51828743. The reversal of 51828721 is 12782815.

It is not a de Polignac number, because 51828721 - 2¹ = 51828719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51828761) 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, 4611 + ... + 11176.

It is an arithmetic number, because the mean of its divisors is an integer number (5099524).

Almost surely, 2^51828721 is an apocalyptic number.

It is an amenable number.

51828721 is a deficient number, since it is larger than the sum of its proper divisors (9365567).

51828721 is a wasteful number, since it uses less digits than its factorization.

51828721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15868 (or 15861 counting only the distinct ones).

The product of its digits is 8960, while the sum is 34.

The square root of 51828721 is about 7199.2166935021. The cubic root of 51828721 is about 372.8408567195.

The spelling of 51828721 in words is "fifty-one million, eight hundred twenty-eight thousand, seven hundred twenty-one".