1021002020191 has 2 divisors, whose sum is σ = 1021002020192. Its totient is φ = 1021002020190.

The previous prime is 1021002020183. The next prime is 1021002020249. The reversal of 1021002020191 is 1910202001201.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1021002020191 - 2³ = 1021002020183 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021002020111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510501010095 + 510501010096.

It is an arithmetic number, because the mean of its divisors is an integer number (510501010096).

Almost surely, 2^{1021002020191} is an apocalyptic number.

1021002020191 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021002020191 is an equidigital number, since it uses as much as digits as its factorization.

1021002020191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 1021002020191 its reverse (1910202001201), we get a palindrome (2931204021392).

The spelling of 1021002020191 in words is "one trillion, twenty-one billion, two million, twenty thousand, one hundred ninety-one".