202120319981 has 2 divisors, whose sum is σ = 202120319982. Its totient is φ = 202120319980.

The previous prime is 202120319927. The next prime is 202120320019. The reversal of 202120319981 is 189913021202.

It is an a-pointer prime, because the next prime (202120320019) can be obtained adding 202120319981 to its sum of digits (38).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 130902858025 + 71217461956 = 361805^2 + 266866^2 .

It is a cyclic number.

It is not a de Polignac number, because 202120319981 - 2⁶ = 202120319917 is a prime.

It is a super-2 number, since 2×202120319981² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (202120319081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101060159990 + 101060159991.

It is an arithmetic number, because the mean of its divisors is an integer number (101060159991).

Almost surely, 2^202120319981 is an apocalyptic number.

It is an amenable number.

202120319981 is a deficient number, since it is larger than the sum of its proper divisors (1).

202120319981 is an equidigital number, since it uses as much as digits as its factorization.

202120319981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 38.

The spelling of 202120319981 in words is "two hundred two billion, one hundred twenty million, three hundred nineteen thousand, nine hundred eighty-one".