821865763 has 2 divisors, whose sum is σ = 821865764. Its totient is φ = 821865762.

The previous prime is 821865761. The next prime is 821865773. The reversal of 821865763 is 367568128.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 821865763 - 2¹ = 821865761 is a prime.

Together with 821865761, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (821865761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410932881 + 410932882.

It is an arithmetic number, because the mean of its divisors is an integer number (410932882).

Almost surely, 2^821865763 is an apocalyptic number.

821865763 is a deficient number, since it is larger than the sum of its proper divisors (1).

821865763 is an equidigital number, since it uses as much as digits as its factorization.

821865763 is an evil number, because the sum of its binary digits is even.

The product of its digits is 483840, while the sum is 46.

The square root of 821865763 is about 28668.2012515609. The cubic root of 821865763 is about 936.6995171895.

The spelling of 821865763 in words is "eight hundred twenty-one million, eight hundred sixty-five thousand, seven hundred sixty-three".