47821817 has 2 divisors, whose sum is σ = 47821818. Its totient is φ = 47821816.

The previous prime is 47821793. The next prime is 47821849. The reversal of 47821817 is 71812874.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38887696 + 8934121 = 6236^2 + 2989^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-47821817 is a prime.

It is not a weakly prime, because it can be changed into another prime (47821877) 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, 23910908 + 23910909.

It is an arithmetic number, because the mean of its divisors is an integer number (23910909).

Almost surely, 2^47821817 is an apocalyptic number.

It is an amenable number.

47821817 is a deficient number, since it is larger than the sum of its proper divisors (1).

47821817 is an equidigital number, since it uses as much as digits as its factorization.

47821817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25088, while the sum is 38.

The square root of 47821817 is about 6915.3320238438. The cubic root of 47821817 is about 362.9738665298.

The spelling of 47821817 in words is "forty-seven million, eight hundred twenty-one thousand, eight hundred seventeen".