202099981 has 2 divisors, whose sum is σ = 202099982. Its totient is φ = 202099980.

The previous prime is 202099921. The next prime is 202099993. The reversal of 202099981 is 189990202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 132043081 + 70056900 = 11491^2 + 8370^2 .

It is a cyclic number.

It is not a de Polignac number, because 202099981 - 2⁷ = 202099853 is a prime.

It is a super-2 number, since 2×202099981² = 81688804640400722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (202099921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101049990 + 101049991.

It is an arithmetic number, because the mean of its divisors is an integer number (101049991).

Almost surely, 2^202099981 is an apocalyptic number.

It is an amenable number.

202099981 is a deficient number, since it is larger than the sum of its proper divisors (1).

202099981 is an equidigital number, since it uses as much as digits as its factorization.

202099981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 202099981 is about 14216.1872877365. The cubic root of 202099981 is about 586.8432193244.

The spelling of 202099981 in words is "two hundred two million, ninety-nine thousand, nine hundred eighty-one".