1781612892401 has 2 divisors, whose sum is σ = 1781612892402. Its totient is φ = 1781612892400.

The previous prime is 1781612892377. The next prime is 1781612892403. The reversal of 1781612892401 is 1042982161871.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1286171469025 + 495441423376 = 1134095^2 + 703876^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1781612892401 is a prime.

Together with 1781612892403, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1781612892401.

It is not a weakly prime, because it can be changed into another prime (1781612892403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 890806446200 + 890806446201.

It is an arithmetic number, because the mean of its divisors is an integer number (890806446201).

Almost surely, 2^{1781612892401} is an apocalyptic number.

It is an amenable number.

1781612892401 is a deficient number, since it is larger than the sum of its proper divisors (1).

1781612892401 is an equidigital number, since it uses as much as digits as its factorization.

1781612892401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 387072, while the sum is 50.

The spelling of 1781612892401 in words is "one trillion, seven hundred eighty-one billion, six hundred twelve million, eight hundred ninety-two thousand, four hundred one".