235491989 has 2 divisors, whose sum is σ = 235491990. Its totient is φ = 235491988.

The previous prime is 235491979. The next prime is 235492001. The reversal of 235491989 is 989194532.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 196840900 + 38651089 = 14030^2 + 6217^2 .

It is a cyclic number.

It is not a de Polignac number, because 235491989 - 2²⁴ = 218714773 is a prime.

It is a super-2 number, since 2×235491989² = 110912953766352242, which 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 (235491929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 117745994 + 117745995.

It is an arithmetic number, because the mean of its divisors is an integer number (117745995).

Almost surely, 2^235491989 is an apocalyptic number.

It is an amenable number.

235491989 is a deficient number, since it is larger than the sum of its proper divisors (1).

235491989 is an equidigital number, since it uses as much as digits as its factorization.

235491989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840, while the sum is 50.

The square root of 235491989 is about 15345.7482385187. The cubic root of 235491989 is about 617.5309268933.

The spelling of 235491989 in words is "two hundred thirty-five million, four hundred ninety-one thousand, nine hundred eighty-nine".