1842781 has 2 divisors, whose sum is σ = 1842782. Its totient is φ = 1842780.

The previous prime is 1842779. The next prime is 1842793. The reversal of 1842781 is 1872481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1625625 + 217156 = 1275^2 + 466^2 .

It is a cyclic number.

It is not a de Polignac number, because 1842781 - 2¹ = 1842779 is a prime.

It is a super-2 number, since 2×1842781² = 6791683627922, which contains 22 as substring.

Together with 1842779, 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 (1842481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 921390 + 921391.

It is an arithmetic number, because the mean of its divisors is an integer number (921391).

2^1842781 is an apocalyptic number.

It is an amenable number.

1842781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1842781 is an equidigital number, since it uses as much as digits as its factorization.

1842781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3584, while the sum is 31.

The square root of 1842781 is about 1357.4906997840. The cubic root of 1842781 is about 122.6002178640.

The spelling of 1842781 in words is "one million, eight hundred forty-two thousand, seven hundred eighty-one".