1821783961901 has 2 divisors, whose sum is σ = 1821783961902. Its totient is φ = 1821783961900.

The previous prime is 1821783961759. The next prime is 1821783961913. The reversal of 1821783961901 is 1091693871281.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 966623248900 + 855160713001 = 983170^2 + 924749^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1821783961901 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1821783960901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910891980950 + 910891980951.

It is an arithmetic number, because the mean of its divisors is an integer number (910891980951).

Almost surely, 2^{1821783961901} is an apocalyptic number.

It is an amenable number.

1821783961901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1821783961901 is an equidigital number, since it uses as much as digits as its factorization.

1821783961901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1306368, while the sum is 56.

The spelling of 1821783961901 in words is "one trillion, eight hundred twenty-one billion, seven hundred eighty-three million, nine hundred sixty-one thousand, nine hundred one".