20196619849457 has 2 divisors, whose sum is σ = 20196619849458. Its totient is φ = 20196619849456.

The previous prime is 20196619849451. The next prime is 20196619849481. The reversal of 20196619849457 is 75494891669102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15376821126241 + 4819798723216 = 3921329^2 + 2195404^2 .

It is a cyclic number.

It is not a de Polignac number, because 20196619849457 - 2¹² = 20196619845361 is a prime.

It is not a weakly prime, because it can be changed into another prime (20196619849451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10098309924728 + 10098309924729.

It is an arithmetic number, because the mean of its divisors is an integer number (10098309924729).

Almost surely, 2^{20196619849457} is an apocalyptic number.

It is an amenable number.

20196619849457 is a deficient number, since it is larger than the sum of its proper divisors (1).

20196619849457 is an equidigital number, since it uses as much as digits as its factorization.

20196619849457 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 235146240, while the sum is 71.

The spelling of 20196619849457 in words is "twenty trillion, one hundred ninety-six billion, six hundred nineteen million, eight hundred forty-nine thousand, four hundred fifty-seven".