385840991 has 4 divisors (see below), whose sum is σ = 386024184. Its totient is φ = 385657800.

The previous prime is 385840979. The next prime is 385841003. The reversal of 385840991 is 199048583.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (385840979) and next prime (385841003).

It is a cyclic number.

It is not a de Polignac number, because 385840991 - 2⁶ = 385840927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (385840951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88400 + ... + 92661.

It is an arithmetic number, because the mean of its divisors is an integer number (96506046).

Almost surely, 2^385840991 is an apocalyptic number.

385840991 is a deficient number, since it is larger than the sum of its proper divisors (183193).

385840991 is a wasteful number, since it uses less digits than its factorization.

385840991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183192.

The product of its (nonzero) digits is 311040, while the sum is 47.

The square root of 385840991 is about 19642.8356150531. The cubic root of 385840991 is about 728.0079492098.

The spelling of 385840991 in words is "three hundred eighty-five million, eight hundred forty thousand, nine hundred ninety-one".