385221690 has 64 divisors (see below), whose sum is σ = 1174014720. Its totient is φ = 88050240.

The previous prime is 385221671. The next prime is 385221701. The reversal of 385221690 is 96122583.

385221690 is a `hidden beast` number, since 38 + 522 + 16 + 90 = 666.

It is a super-2 number, since 2×385221690² = 296791500892912200, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 100021 + ... + 103800.

It is an arithmetic number, because the mean of its divisors is an integer number (18343980).

Almost surely, 2^385221690 is an apocalyptic number.

385221690 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

385221690 is an abundant number, since it is smaller than the sum of its proper divisors (788793030).

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

385221690 is a wasteful number, since it uses less digits than its factorization.

385221690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203844 (or 203838 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 385221690 is about 19627.0652416504. The cubic root of 385221690 is about 727.6182398952.

The spelling of 385221690 in words is "three hundred eighty-five million, two hundred twenty-one thousand, six hundred ninety".