2645104239781 has 2 divisors, whose sum is σ = 2645104239782. Its totient is φ = 2645104239780.

The previous prime is 2645104239763. The next prime is 2645104239839. The reversal of 2645104239781 is 1879324015462.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2096223291556 + 548880948225 = 1447834^2 + 740865^2 .

It is a cyclic number.

It is not a de Polignac number, because 2645104239781 - 2¹³ = 2645104231589 is a prime.

It is a super-2 number, since 2×2645104239781² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2645104236781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1322552119890 + 1322552119891.

It is an arithmetic number, because the mean of its divisors is an integer number (1322552119891).

It is a 1-persistent number, because it is pandigital, but 2⋅2645104239781 = 5290208479562 is not.

Almost surely, 2^{2645104239781} is an apocalyptic number.

It is an amenable number.

2645104239781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2645104239781 is an equidigital number, since it uses as much as digits as its factorization.

2645104239781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2903040, while the sum is 52.

The spelling of 2645104239781 in words is "two trillion, six hundred forty-five billion, one hundred four million, two hundred thirty-nine thousand, seven hundred eighty-one".