1964594942521 has 2 divisors, whose sum is σ = 1964594942522. Its totient is φ = 1964594942520.

The previous prime is 1964594942509. The next prime is 1964594942623. The reversal of 1964594942521 is 1252494954691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1159636074496 + 804958868025 = 1076864^2 + 897195^2 .

It is a cyclic number.

It is not a de Polignac number, because 1964594942521 - 2⁵ = 1964594942489 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1964594942521.

It is not a weakly prime, because it can be changed into another prime (1964594942021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 982297471260 + 982297471261.

It is an arithmetic number, because the mean of its divisors is an integer number (982297471261).

Almost surely, 2^{1964594942521} is an apocalyptic number.

It is an amenable number.

1964594942521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1964594942521 is an equidigital number, since it uses as much as digits as its factorization.

1964594942521 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 1964594942521 in words is "one trillion, nine hundred sixty-four billion, five hundred ninety-four million, nine hundred forty-two thousand, five hundred twenty-one".