20011221229997 has 2 divisors, whose sum is σ = 20011221229998. Its totient is φ = 20011221229996.

The previous prime is 20011221229963. The next prime is 20011221230003. The reversal of 20011221229997 is 79992212211002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19543729047241 + 467492182756 = 4420829^2 + 683734^2 .

It is a cyclic number.

It is not a de Polignac number, because 20011221229997 - 2²⁸ = 20010952794541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20011221222997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005610614998 + 10005610614999.

It is an arithmetic number, because the mean of its divisors is an integer number (10005610614999).

Almost surely, 2^{20011221229997} is an apocalyptic number.

It is an amenable number.

20011221229997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011221229997 is an equidigital number, since it uses as much as digits as its factorization.

20011221229997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 47.

The spelling of 20011221229997 in words is "twenty trillion, eleven billion, two hundred twenty-one million, two hundred twenty-nine thousand, nine hundred ninety-seven".