1640240401 has 2 divisors, whose sum is σ = 1640240402. Its totient is φ = 1640240400.

The previous prime is 1640240353. The next prime is 1640240419. The reversal of 1640240401 is 1040420461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1609935376 + 30305025 = 40124^2 + 5505^2 .

It is an emirp because it is prime and its reverse (1040420461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1640240401 - 2¹⁵ = 1640207633 is a prime.

It is not a weakly prime, because it can be changed into another prime (1640241401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820120200 + 820120201.

It is an arithmetic number, because the mean of its divisors is an integer number (820120201).

Almost surely, 2^1640240401 is an apocalyptic number.

It is an amenable number.

1640240401 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640240401 is an equidigital number, since it uses as much as digits as its factorization.

1640240401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 1640240401 is about 40499.8814936538. The cubic root of 1640240401 is about 1179.3313268411.

Adding to 1640240401 its reverse (1040420461), we get a palindrome (2680660862).

The spelling of 1640240401 in words is "one billion, six hundred forty million, two hundred forty thousand, four hundred one".