1804420781 has 2 divisors, whose sum is σ = 1804420782. Its totient is φ = 1804420780.

The previous prime is 1804420711. The next prime is 1804420801. The reversal of 1804420781 is 1870244081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1541818756 + 262602025 = 39266^2 + 16205^2 .

It is a cyclic number.

It is not a de Polignac number, because 1804420781 - 2¹⁴ = 1804404397 is a prime.

It is a super-2 number, since 2×1804420781² = 6511868709809299922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1804420711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 902210390 + 902210391.

It is an arithmetic number, because the mean of its divisors is an integer number (902210391).

Almost surely, 2^1804420781 is an apocalyptic number.

It is an amenable number.

1804420781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1804420781 is an equidigital number, since it uses as much as digits as its factorization.

1804420781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14336, while the sum is 35.

The square root of 1804420781 is about 42478.4743252391. The cubic root of 1804420781 is about 1217.4354398822.

The spelling of 1804420781 in words is "one billion, eight hundred four million, four hundred twenty thousand, seven hundred eighty-one".