239201981 has 2 divisors, whose sum is σ = 239201982. Its totient is φ = 239201980.

The previous prime is 239201927. The next prime is 239201999. The reversal of 239201981 is 189102932.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 236083225 + 3118756 = 15365^2 + 1766^2 .

It is a cyclic number.

It is not a de Polignac number, because 239201981 - 2¹⁸ = 238939837 is a prime.

It is a super-2 number, since 2×239201981² = 114435175428648722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (239201581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 119600990 + 119600991.

It is an arithmetic number, because the mean of its divisors is an integer number (119600991).

Almost surely, 2^239201981 is an apocalyptic number.

It is an amenable number.

239201981 is a deficient number, since it is larger than the sum of its proper divisors (1).

239201981 is an equidigital number, since it uses as much as digits as its factorization.

239201981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 239201981 is about 15466.1559865404. The cubic root of 239201981 is about 620.7569500830.

The spelling of 239201981 in words is "two hundred thirty-nine million, two hundred one thousand, nine hundred eighty-one".