388449690 has 32 divisors (see below), whose sum is σ = 937500480. Its totient is φ = 103006464.

The previous prime is 388449679. The next prime is 388449709. The reversal of 388449690 is 96944883.

It is a happy number.

It is a super-2 number, since 2×388449690² = 301786323322192200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30799 + ... + 41538.

It is an arithmetic number, because the mean of its divisors is an integer number (29296890).

Almost surely, 2^388449690 is an apocalyptic number.

388449690 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

388449690 is an abundant number, since it is smaller than the sum of its proper divisors (549050790).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

388449690 is a wasteful number, since it uses less digits than its factorization.

388449690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72526.

The product of its (nonzero) digits is 1492992, while the sum is 51.

The square root of 388449690 is about 19709.1270735160. The cubic root of 388449690 is about 729.6449702907.

The spelling of 388449690 in words is "three hundred eighty-eight million, four hundred forty-nine thousand, six hundred ninety".