387420509 has 6 divisors (see below), whose sum is σ = 450672894. Its totient is φ = 332074680.

The previous prime is 387420499. The next prime is 387420559. The reversal of 387420509 is 905024783.

It can be written as a sum of positive squares in only one way, i.e., 369485284 + 17935225 = 19222^2 + 4235^2 .

It is not a de Polignac number, because 387420509 - 2¹² = 387416413 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (387420559) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3953222 + ... + 3953319.

It is an arithmetic number, because the mean of its divisors is an integer number (75112149).

Almost surely, 2^387420509 is an apocalyptic number.

It is an amenable number.

387420509 is a deficient number, since it is larger than the sum of its proper divisors (63252385).

387420509 is an equidigital number, since it uses as much as digits as its factorization.

387420509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7906555 (or 7906548 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 387420509 is about 19683.0005080526. Note that the first 3 decimals coincide. The cubic root of 387420509 is about 729.0000125445. Note that the first 4 decimals are identical.

The spelling of 387420509 in words is "three hundred eighty-seven million, four hundred twenty thousand, five hundred nine".