821619047 has 2 divisors, whose sum is σ = 821619048. Its totient is φ = 821619046.

The previous prime is 821619013. The next prime is 821619067. The reversal of 821619047 is 740916128.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 821619047 - 2¹⁶ = 821553511 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 821619047.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821619067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410809523 + 410809524.

It is an arithmetic number, because the mean of its divisors is an integer number (410809524).

Almost surely, 2^821619047 is an apocalyptic number.

821619047 is a deficient number, since it is larger than the sum of its proper divisors (1).

821619047 is an equidigital number, since it uses as much as digits as its factorization.

821619047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 821619047 is about 28663.8979728857. The cubic root of 821619047 is about 936.6057784888.

The spelling of 821619047 in words is "eight hundred twenty-one million, six hundred nineteen thousand, forty-seven".