340724821 has 2 divisors, whose sum is σ = 340724822. Its totient is φ = 340724820.

The previous prime is 340724809. The next prime is 340724837. The reversal of 340724821 is 128427043.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 288524196 + 52200625 = 16986^2 + 7225^2 .

It is a cyclic number.

It is not a de Polignac number, because 340724821 - 2¹⁷ = 340593749 is a prime.

It is equal to p_18331663 and since 340724821 and 18331663 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (340724851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170362410 + 170362411.

It is an arithmetic number, because the mean of its divisors is an integer number (170362411).

Almost surely, 2^340724821 is an apocalyptic number.

It is an amenable number.

340724821 is a deficient number, since it is larger than the sum of its proper divisors (1).

340724821 is an equidigital number, since it uses as much as digits as its factorization.

340724821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10752, while the sum is 31.

The square root of 340724821 is about 18458.7329196779. The cubic root of 340724821 is about 698.4488243715.

The spelling of 340724821 in words is "three hundred forty million, seven hundred twenty-four thousand, eight hundred twenty-one".