387489989 has 2 divisors, whose sum is σ = 387489990. Its totient is φ = 387489988.

The previous prime is 387489961. The next prime is 387490003. The reversal of 387489989 is 989984783.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 382867489 + 4622500 = 19567^2 + 2150^2 .

It is a cyclic number.

It is not a de Polignac number, because 387489989 - 2²⁰ = 386441413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (387489689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 193744994 + 193744995.

It is an arithmetic number, because the mean of its divisors is an integer number (193744995).

Almost surely, 2^387489989 is an apocalyptic number.

It is an amenable number.

387489989 is a deficient number, since it is larger than the sum of its proper divisors (1).

387489989 is an equidigital number, since it uses as much as digits as its factorization.

387489989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31352832, while the sum is 65.

The square root of 387489989 is about 19684.7654037329. The cubic root of 387489989 is about 729.0435895640.

The spelling of 387489989 in words is "three hundred eighty-seven million, four hundred eighty-nine thousand, nine hundred eighty-nine".