385242721 has 2 divisors, whose sum is σ = 385242722. Its totient is φ = 385242720.

The previous prime is 385242679. The next prime is 385242731. The reversal of 385242721 is 127242583.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 383180625 + 2062096 = 19575^2 + 1436^2 .

It is a cyclic number.

It is not a de Polignac number, because 385242721 - 2¹¹ = 385240673 is a prime.

It is not a weakly prime, because it can be changed into another prime (385242731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 192621360 + 192621361.

It is an arithmetic number, because the mean of its divisors is an integer number (192621361).

Almost surely, 2^385242721 is an apocalyptic number.

It is an amenable number.

385242721 is a deficient number, since it is larger than the sum of its proper divisors (1).

385242721 is an equidigital number, since it uses as much as digits as its factorization.

385242721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26880, while the sum is 34.

The square root of 385242721 is about 19627.6009996128. The cubic root of 385242721 is about 727.6314809813.

The spelling of 385242721 in words is "three hundred eighty-five million, two hundred forty-two thousand, seven hundred twenty-one".