387221389 has 2 divisors, whose sum is σ = 387221390. Its totient is φ = 387221388.

The previous prime is 387221383. The next prime is 387221411. The reversal of 387221389 is 983122783.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 336098889 + 51122500 = 18333^2 + 7150^2 .

It is an emirp because it is prime and its reverse (983122783) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 387221389 - 2⁵ = 387221357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (387221383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 193610694 + 193610695.

It is an arithmetic number, because the mean of its divisors is an integer number (193610695).

Almost surely, 2^387221389 is an apocalyptic number.

It is an amenable number.

387221389 is a deficient number, since it is larger than the sum of its proper divisors (1).

387221389 is an equidigital number, since it uses as much as digits as its factorization.

387221389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 43.

The square root of 387221389 is about 19677.9416860606. The cubic root of 387221389 is about 728.8750980094.

The spelling of 387221389 in words is "three hundred eighty-seven million, two hundred twenty-one thousand, three hundred eighty-nine".