1780493989 has 2 divisors, whose sum is σ = 1780493990. Its totient is φ = 1780493988.

The previous prime is 1780493969. The next prime is 1780493993. The reversal of 1780493989 is 9893940871.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1475712225 + 304781764 = 38415^2 + 17458^2 .

It is a cyclic number.

It is not a de Polignac number, because 1780493989 - 2¹³ = 1780485797 is a prime.

It is a super-3 number, since 3×1780493989³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1780493969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 890246994 + 890246995.

It is an arithmetic number, because the mean of its divisors is an integer number (890246995).

Almost surely, 2^1780493989 is an apocalyptic number.

It is an amenable number.

1780493989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1780493989 is an equidigital number, since it uses as much as digits as its factorization.

1780493989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3919104, while the sum is 58.

The square root of 1780493989 is about 42195.9001444453. The cubic root of 1780493989 is about 1212.0303750280.

The spelling of 1780493989 in words is "one billion, seven hundred eighty million, four hundred ninety-three thousand, nine hundred eighty-nine".