1820949797533 has 2 divisors, whose sum is σ = 1820949797534. Its totient is φ = 1820949797532.

The previous prime is 1820949797531. The next prime is 1820949797561. The reversal of 1820949797533 is 3357979490281.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1457722999044 + 363226798489 = 1207362^2 + 602683^2 .

It is a cyclic number.

It is not a de Polignac number, because 1820949797533 - 2¹ = 1820949797531 is a prime.

Together with 1820949797531, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1820949797531) 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, 910474898766 + 910474898767.

It is an arithmetic number, because the mean of its divisors is an integer number (910474898767).

Almost surely, 2^{1820949797533} is an apocalyptic number.

It is an amenable number.

1820949797533 is a deficient number, since it is larger than the sum of its proper divisors (1).

1820949797533 is an equidigital number, since it uses as much as digits as its factorization.

1820949797533 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 102876480, while the sum is 67.

The spelling of 1820949797533 in words is "one trillion, eight hundred twenty billion, nine hundred forty-nine million, seven hundred ninety-seven thousand, five hundred thirty-three".