1820416195991 has 2 divisors, whose sum is σ = 1820416195992. Its totient is φ = 1820416195990.

The previous prime is 1820416195981. The next prime is 1820416196021. The reversal of 1820416195991 is 1995916140281.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1820416195991 - 2¹⁰ = 1820416194967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1820416195981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910208097995 + 910208097996.

It is an arithmetic number, because the mean of its divisors is an integer number (910208097996).

Almost surely, 2^{1820416195991} is an apocalyptic number.

1820416195991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1820416195991 is an equidigital number, since it uses as much as digits as its factorization.

1820416195991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1399680, while the sum is 56.

The spelling of 1820416195991 in words is "one trillion, eight hundred twenty billion, four hundred sixteen million, one hundred ninety-five thousand, nine hundred ninety-one".