1020021220091 has 2 divisors, whose sum is σ = 1020021220092. Its totient is φ = 1020021220090.

The previous prime is 1020021220079. The next prime is 1020021220111. The reversal of 1020021220091 is 1900221200201.

It is a happy number.

It is an a-pointer prime, because the next prime (1020021220111) can be obtained adding 1020021220091 to its sum of digits (20).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1020021220091 - 2¹⁰ = 1020021219067 is a prime.

It is not a weakly prime, because it can be changed into another prime (1020021220021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510010610045 + 510010610046.

It is an arithmetic number, because the mean of its divisors is an integer number (510010610046).

Almost surely, 2^{1020021220091} is an apocalyptic number.

1020021220091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1020021220091 is an equidigital number, since it uses as much as digits as its factorization.

1020021220091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 1020021220091 its reverse (1900221200201), we get a palindrome (2920242420292).

The spelling of 1020021220091 in words is "one trillion, twenty billion, twenty-one million, two hundred twenty thousand, ninety-one".