20197990801 has 2 divisors, whose sum is σ = 20197990802. Its totient is φ = 20197990800.

The previous prime is 20197990781. The next prime is 20197990817. The reversal of 20197990801 is 10809979102.

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., 17331459201 + 2866531600 = 131649^2 + 53540^2 .

It is a cyclic number.

It is not a de Polignac number, because 20197990801 - 2¹¹ = 20197988753 is a prime.

It is not a weakly prime, because it can be changed into another prime (20197993801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10098995400 + 10098995401.

It is an arithmetic number, because the mean of its divisors is an integer number (10098995401).

Almost surely, 2^20197990801 is an apocalyptic number.

It is an amenable number.

20197990801 is a deficient number, since it is larger than the sum of its proper divisors (1).

20197990801 is an equidigital number, since it uses as much as digits as its factorization.

20197990801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81648, while the sum is 46.

The spelling of 20197990801 in words is "twenty billion, one hundred ninety-seven million, nine hundred ninety thousand, eight hundred one".