388442690 has 16 divisors (see below), whose sum is σ = 740326392. Its totient is φ = 146237184.

The previous prime is 388442689. The next prime is 388442723. The reversal of 388442690 is 96244883.

It can be written as a sum of positive squares in 4 ways, for example, as 264810529 + 123632161 = 16273^2 + 11119^2 .

It is a super-2 number, since 2×388442690² = 301775446828872200, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1142309 + ... + 1142648.

Almost surely, 2^388442690 is an apocalyptic number.

388442690 is a deficient number, since it is larger than the sum of its proper divisors (351883702).

388442690 is a wasteful number, since it uses less digits than its factorization.

388442690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2284981.

The product of its (nonzero) digits is 331776, while the sum is 44.

The square root of 388442690 is about 19708.9494900160. The cubic root of 388442690 is about 729.6405874448.

The spelling of 388442690 in words is "three hundred eighty-eight million, four hundred forty-two thousand, six hundred ninety".