1809440641 has 2 divisors, whose sum is σ = 1809440642. Its totient is φ = 1809440640.

The previous prime is 1809440629. The next prime is 1809440651. The reversal of 1809440641 is 1460449081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1274490000 + 534950641 = 35700^2 + 23129^2 .

It is a cyclic number.

It is not a de Polignac number, because 1809440641 - 2¹¹ = 1809438593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1809440641.

It is not a weakly prime, because it can be changed into another prime (1809440651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 904720320 + 904720321.

It is an arithmetic number, because the mean of its divisors is an integer number (904720321).

Almost surely, 2^1809440641 is an apocalyptic number.

It is an amenable number.

1809440641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1809440641 is an equidigital number, since it uses as much as digits as its factorization.

1809440641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 1809440641 is about 42537.5203908267. The cubic root of 1809440641 is about 1218.5633543639.

The spelling of 1809440641 in words is "one billion, eight hundred nine million, four hundred forty thousand, six hundred forty-one".