51825821 has 2 divisors, whose sum is σ = 51825822. Its totient is φ = 51825820.

The previous prime is 51825803. The next prime is 51825841. The reversal of 51825821 is 12852815.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26925721 + 24900100 = 5189^2 + 4990^2 .

It is a cyclic number.

It is not a de Polignac number, because 51825821 - 2⁶ = 51825757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51825841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25912910 + 25912911.

It is an arithmetic number, because the mean of its divisors is an integer number (25912911).

Almost surely, 2^51825821 is an apocalyptic number.

It is an amenable number.

51825821 is a deficient number, since it is larger than the sum of its proper divisors (1).

51825821 is an equidigital number, since it uses as much as digits as its factorization.

51825821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6400, while the sum is 32.

The square root of 51825821 is about 7199.0152798838. The cubic root of 51825821 is about 372.8339026689.

The spelling of 51825821 in words is "fifty-one million, eight hundred twenty-five thousand, eight hundred twenty-one".