384145721 has 2 divisors, whose sum is σ = 384145722. Its totient is φ = 384145720.

The previous prime is 384145717. The next prime is 384145763. The reversal of 384145721 is 127541483.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 361000000 + 23145721 = 19000^2 + 4811^2 .

It is a cyclic number.

It is not a de Polignac number, because 384145721 - 2² = 384145717 is a prime.

It is not a weakly prime, because it can be changed into another prime (384145771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 192072860 + 192072861.

It is an arithmetic number, because the mean of its divisors is an integer number (192072861).

Almost surely, 2^384145721 is an apocalyptic number.

It is an amenable number.

384145721 is a deficient number, since it is larger than the sum of its proper divisors (1).

384145721 is an equidigital number, since it uses as much as digits as its factorization.

384145721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26880, while the sum is 35.

The square root of 384145721 is about 19599.6357364110. The cubic root of 384145721 is about 726.9401673906.

The spelling of 384145721 in words is "three hundred eighty-four million, one hundred forty-five thousand, seven hundred twenty-one".