2021195807797 has 2 divisors, whose sum is σ = 2021195807798. Its totient is φ = 2021195807796.

The previous prime is 2021195807791. The next prime is 2021195807831. The reversal of 2021195807797 is 7977085911202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1578224363076 + 442971444721 = 1256274^2 + 665561^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021195807797 - 2³ = 2021195807789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021195807791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010597903898 + 1010597903899.

It is an arithmetic number, because the mean of its divisors is an integer number (1010597903899).

Almost surely, 2^{2021195807797} is an apocalyptic number.

It is an amenable number.

2021195807797 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021195807797 is an equidigital number, since it uses as much as digits as its factorization.

2021195807797 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4445280, while the sum is 58.

The spelling of 2021195807797 in words is "two trillion, twenty-one billion, one hundred ninety-five million, eight hundred seven thousand, seven hundred ninety-seven".