820856846883631 has 2 divisors, whose sum is σ = 820856846883632. Its totient is φ = 820856846883630.

The previous prime is 820856846883559. The next prime is 820856846883637. The reversal of 820856846883631 is 136388648658028.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 820856846883631 - 2²⁷ = 820856712665903 is a prime.

It is a super-2 number, since 2×820856846883631² (a number of 31 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820856846883637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410428423441815 + 410428423441816.

It is an arithmetic number, because the mean of its divisors is an integer number (410428423441816).

Almost surely, 2^{820856846883631} is an apocalyptic number.

820856846883631 is a deficient number, since it is larger than the sum of its proper divisors (1).

820856846883631 is an equidigital number, since it uses as much as digits as its factorization.

820856846883631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2548039680, while the sum is 76.

The spelling of 820856846883631 in words is "eight hundred twenty trillion, eight hundred fifty-six billion, eight hundred forty-six million, eight hundred eighty-three thousand, six hundred thirty-one".