10211220021991 has 2 divisors, whose sum is σ = 10211220021992. Its totient is φ = 10211220021990.

The previous prime is 10211220021983. The next prime is 10211220022013. The reversal of 10211220021991 is 19912002211201.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 10211220021991 - 2³ = 10211220021983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10211220021901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5105610010995 + 5105610010996.

It is an arithmetic number, because the mean of its divisors is an integer number (5105610010996).

Almost surely, 2^{10211220021991} is an apocalyptic number.

10211220021991 is a deficient number, since it is larger than the sum of its proper divisors (1).

10211220021991 is an equidigital number, since it uses as much as digits as its factorization.

10211220021991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 31.

The spelling of 10211220021991 in words is "ten trillion, two hundred eleven billion, two hundred twenty million, twenty-one thousand, nine hundred ninety-one".