1821630486493 has 2 divisors, whose sum is σ = 1821630486494. Its totient is φ = 1821630486492.

The previous prime is 1821630486463. The next prime is 1821630486503. The reversal of 1821630486493 is 3946840361281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1650397563684 + 171232922809 = 1284678^2 + 413803^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1821630486493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1821630486413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910815243246 + 910815243247.

It is an arithmetic number, because the mean of its divisors is an integer number (910815243247).

Almost surely, 2^{1821630486493} is an apocalyptic number.

It is an amenable number.

1821630486493 is a deficient number, since it is larger than the sum of its proper divisors (1).

1821630486493 is an equidigital number, since it uses as much as digits as its factorization.

1821630486493 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5971968, while the sum is 55.

The spelling of 1821630486493 in words is "one trillion, eight hundred twenty-one billion, six hundred thirty million, four hundred eighty-six thousand, four hundred ninety-three".