387512221 has 2 divisors, whose sum is σ = 387512222. Its totient is φ = 387512220.

The previous prime is 387512219. The next prime is 387512233. The reversal of 387512221 is 122215783.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 387499225 + 12996 = 19685^2 + 114^2 .

It is a cyclic number.

It is not a de Polignac number, because 387512221 - 2¹ = 387512219 is a prime.

Together with 387512219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (387512291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 193756110 + 193756111.

It is an arithmetic number, because the mean of its divisors is an integer number (193756111).

Almost surely, 2^387512221 is an apocalyptic number.

It is an amenable number.

387512221 is a deficient number, since it is larger than the sum of its proper divisors (1).

387512221 is an equidigital number, since it uses as much as digits as its factorization.

387512221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 31.

The square root of 387512221 is about 19685.3300962925. The cubic root of 387512221 is about 729.0575321067.

The spelling of 387512221 in words is "three hundred eighty-seven million, five hundred twelve thousand, two hundred twenty-one".