1778141 has 2 divisors, whose sum is σ = 1778142. Its totient is φ = 1778140.

The previous prime is 1778137. The next prime is 1778159. The reversal of 1778141 is 1418771.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1552516 + 225625 = 1246^2 + 475^2 .

It is an emirp because it is prime and its reverse (1418771) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1778141 - 2² = 1778137 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1778111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 889070 + 889071.

It is an arithmetic number, because the mean of its divisors is an integer number (889071).

2^1778141 is an apocalyptic number.

It is an amenable number.

1778141 is a deficient number, since it is larger than the sum of its proper divisors (1).

1778141 is an equidigital number, since it uses as much as digits as its factorization.

1778141 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1568, while the sum is 29.

The square root of 1778141 is about 1333.4695347101. The cubic root of 1778141 is about 121.1496225259.

The spelling of 1778141 in words is "one million, seven hundred seventy-eight thousand, one hundred forty-one".