21001002220091 has 2 divisors, whose sum is σ = 21001002220092. Its totient is φ = 21001002220090.

The previous prime is 21001002220067. The next prime is 21001002220111. The reversal of 21001002220091 is 19002220010012.

It is a happy number.

It is an a-pointer prime, because the next prime (21001002220111) can be obtained adding 21001002220091 to its sum of digits (20).

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21001002220091 is a prime.

It is a super-2 number, since 2×21001002220091² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21001002220021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500501110045 + 10500501110046.

It is an arithmetic number, because the mean of its divisors is an integer number (10500501110046).

Almost surely, 2^{21001002220091} is an apocalyptic number.

21001002220091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001002220091 is an equidigital number, since it uses as much as digits as its factorization.

21001002220091 is an odious number, because the sum of its binary digits is odd.

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

The spelling of 21001002220091 in words is "twenty-one trillion, one billion, two million, two hundred twenty thousand, ninety-one".