3984926512561 has 2 divisors, whose sum is σ = 3984926512562. Its totient is φ = 3984926512560.

The previous prime is 3984926512549. The next prime is 3984926512573. The reversal of 3984926512561 is 1652156294893.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (3984926512549) and next prime (3984926512573).

It can be written as a sum of positive squares in only one way, i.e., 3940760968225 + 44165544336 = 1985135^2 + 210156^2 .

It is a cyclic number.

It is not a de Polignac number, because 3984926512561 - 2¹⁷ = 3984926381489 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 3984926512561.

It is not a weakly prime, because it can be changed into another prime (3984926512531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1992463256280 + 1992463256281.

It is an arithmetic number, because the mean of its divisors is an integer number (1992463256281).

Almost surely, 2^{3984926512561} is an apocalyptic number.

It is an amenable number.

3984926512561 is a deficient number, since it is larger than the sum of its proper divisors (1).

3984926512561 is an equidigital number, since it uses as much as digits as its factorization.

3984926512561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27993600, while the sum is 61.

The spelling of 3984926512561 in words is "three trillion, nine hundred eighty-four billion, nine hundred twenty-six million, five hundred twelve thousand, five hundred sixty-one".