385221709 has 2 divisors, whose sum is σ = 385221710. Its totient is φ = 385221708.

The previous prime is 385221701. The next prime is 385221731. The reversal of 385221709 is 907122583.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 215649225 + 169572484 = 14685^2 + 13022^2 .

It is a cyclic number.

It is not a de Polignac number, because 385221709 - 2³ = 385221701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (385221701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 192610854 + 192610855.

It is an arithmetic number, because the mean of its divisors is an integer number (192610855).

Almost surely, 2^385221709 is an apocalyptic number.

It is an amenable number.

385221709 is a deficient number, since it is larger than the sum of its proper divisors (1).

385221709 is an equidigital number, since it uses as much as digits as its factorization.

385221709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 385221709 is about 19627.0657256759. The cubic root of 385221709 is about 727.6182518577.

The spelling of 385221709 in words is "three hundred eighty-five million, two hundred twenty-one thousand, seven hundred nine".