651384821 has 2 divisors, whose sum is σ = 651384822. Its totient is φ = 651384820.

The previous prime is 651384751. The next prime is 651384827. The reversal of 651384821 is 128483156.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 619462321 + 31922500 = 24889^2 + 5650^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-651384821 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (651384827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325692410 + 325692411.

It is an arithmetic number, because the mean of its divisors is an integer number (325692411).

Almost surely, 2^651384821 is an apocalyptic number.

It is an amenable number.

651384821 is a deficient number, since it is larger than the sum of its proper divisors (1).

651384821 is an equidigital number, since it uses as much as digits as its factorization.

651384821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46080, while the sum is 38.

The square root of 651384821 is about 25522.2416922965. The cubic root of 651384821 is about 866.8538413447.

The spelling of 651384821 in words is "six hundred fifty-one million, three hundred eighty-four thousand, eight hundred twenty-one".