20093981 has 2 divisors, whose sum is σ = 20093982. Its totient is φ = 20093980.

The previous prime is 20093947. The next prime is 20093987. The reversal of 20093981 is 18939002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10272025 + 9821956 = 3205^2 + 3134^2 .

It is a cyclic number.

It is not a de Polignac number, because 20093981 - 2⁶ = 20093917 is a prime.

It is a super-2 number, since 2×20093981² = 807536144856722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20093987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10046990 + 10046991.

It is an arithmetic number, because the mean of its divisors is an integer number (10046991).

Almost surely, 2^20093981 is an apocalyptic number.

It is an amenable number.

20093981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20093981 is an equidigital number, since it uses as much as digits as its factorization.

20093981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 20093981 is about 4482.6310354523. The cubic root of 20093981 is about 271.8662702266.

The spelling of 20093981 in words is "twenty million, ninety-three thousand, nine hundred eighty-one".