516417821 has 2 divisors, whose sum is σ = 516417822. Its totient is φ = 516417820.

The previous prime is 516417817. The next prime is 516417829. The reversal of 516417821 is 128714615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 319015321 + 197402500 = 17861^2 + 14050^2 .

It is a cyclic number.

It is not a de Polignac number, because 516417821 - 2² = 516417817 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 (516417829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 258208910 + 258208911.

It is an arithmetic number, because the mean of its divisors is an integer number (258208911).

Almost surely, 2^516417821 is an apocalyptic number.

It is an amenable number.

516417821 is a deficient number, since it is larger than the sum of its proper divisors (1).

516417821 is an equidigital number, since it uses as much as digits as its factorization.

516417821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440, while the sum is 35.

The square root of 516417821 is about 22724.8282941808. The cubic root of 516417821 is about 802.2943620256.

The spelling of 516417821 in words is "five hundred sixteen million, four hundred seventeen thousand, eight hundred twenty-one".