390128215 has 4 divisors (see below), whose sum is σ = 468153864. Its totient is φ = 312102568.

The previous prime is 390128209. The next prime is 390128227. The reversal of 390128215 is 512821093.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 390128215 - 2¹³ = 390120023 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39012817 + ... + 39012826.

It is an arithmetic number, because the mean of its divisors is an integer number (117038466).

Almost surely, 2^390128215 is an apocalyptic number.

390128215 is a deficient number, since it is larger than the sum of its proper divisors (78025649).

390128215 is an equidigital number, since it uses as much as digits as its factorization.

390128215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78025648.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 390128215 is about 19751.6636008211. The cubic root of 390128215 is about 730.6944133518.

The spelling of 390128215 in words is "three hundred ninety million, one hundred twenty-eight thousand, two hundred fifteen".