238978661 has 2 divisors, whose sum is σ = 238978662. Its totient is φ = 238978660.

The previous prime is 238978651. The next prime is 238978679. The reversal of 238978661 is 166879832.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 231222436 + 7756225 = 15206^2 + 2785^2 .

It is a cyclic number.

It is not a de Polignac number, because 238978661 - 2¹⁰ = 238977637 is a prime.

It is a super-2 number, since 2×238978661² = 114221600826705842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (238978631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 119489330 + 119489331.

It is an arithmetic number, because the mean of its divisors is an integer number (119489331).

Almost surely, 2^238978661 is an apocalyptic number.

It is an amenable number.

238978661 is a deficient number, since it is larger than the sum of its proper divisors (1).

238978661 is an equidigital number, since it uses as much as digits as its factorization.

238978661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 50.

The square root of 238978661 is about 15458.9346657524. The cubic root of 238978661 is about 620.5637094794.

The spelling of 238978661 in words is "two hundred thirty-eight million, nine hundred seventy-eight thousand, six hundred sixty-one".