385909661 has 2 divisors, whose sum is σ = 385909662. Its totient is φ = 385909660.

The previous prime is 385909591. The next prime is 385909681. The reversal of 385909661 is 166909583.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 317516761 + 68392900 = 17819^2 + 8270^2 .

It is an emirp because it is prime and its reverse (166909583) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-385909661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (385909681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 192954830 + 192954831.

It is an arithmetic number, because the mean of its divisors is an integer number (192954831).

Almost surely, 2^385909661 is an apocalyptic number.

It is an amenable number.

385909661 is a deficient number, since it is larger than the sum of its proper divisors (1).

385909661 is an equidigital number, since it uses as much as digits as its factorization.

385909661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 349920, while the sum is 47.

The square root of 385909661 is about 19644.5835028386. The cubic root of 385909661 is about 728.0511356878.

The spelling of 385909661 in words is "three hundred eighty-five million, nine hundred nine thousand, six hundred sixty-one".