1966277256401 has 2 divisors, whose sum is σ = 1966277256402. Its totient is φ = 1966277256400.

The previous prime is 1966277256353. The next prime is 1966277256413. The reversal of 1966277256401 is 1046527726691.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1522422838225 + 443854418176 = 1233865^2 + 666224^2 .

It is a cyclic number.

It is not a de Polignac number, because 1966277256401 - 2³⁰ = 1965203514577 is a prime.

It is not a weakly prime, because it can be changed into another prime (1966277256491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 983138628200 + 983138628201.

It is an arithmetic number, because the mean of its divisors is an integer number (983138628201).

Almost surely, 2^{1966277256401} is an apocalyptic number.

It is an amenable number.

1966277256401 is a deficient number, since it is larger than the sum of its proper divisors (1).

1966277256401 is an equidigital number, since it uses as much as digits as its factorization.

1966277256401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7620480, while the sum is 56.

The spelling of 1966277256401 in words is "one trillion, nine hundred sixty-six billion, two hundred seventy-seven million, two hundred fifty-six thousand, four hundred one".