1785728100049 has 2 divisors, whose sum is σ = 1785728100050. Its totient is φ = 1785728100048.

The previous prime is 1785728100047. The next prime is 1785728100097. The reversal of 1785728100049 is 9400018275871.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1296539763649 + 489188336400 = 1138657^2 + 699420^2 .

It is a cyclic number.

It is not a de Polignac number, because 1785728100049 - 2¹ = 1785728100047 is a prime.

It is a super-2 number, since 2×1785728100049² (a number of 25 digits) contains 22 as substring.

Together with 1785728100047, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1785728099969 and 1785728100005.

It is not a weakly prime, because it can be changed into another prime (1785728100043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 892864050024 + 892864050025.

It is an arithmetic number, because the mean of its divisors is an integer number (892864050025).

Almost surely, 2^{1785728100049} is an apocalyptic number.

It is an amenable number.

1785728100049 is a deficient number, since it is larger than the sum of its proper divisors (1).

1785728100049 is an equidigital number, since it uses as much as digits as its factorization.

1785728100049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1128960, while the sum is 52.

The spelling of 1785728100049 in words is "one trillion, seven hundred eighty-five billion, seven hundred twenty-eight million, one hundred thousand, forty-nine".