395666820 has 72 divisors (see below), whose sum is σ = 1201835544. Its totient is φ = 105366528.

The previous prime is 395666809. The next prime is 395666833. The reversal of 395666820 is 28666593.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 77686596 + 317980224 = 8814^2 + 17832^2 .

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 221772 + ... + 223548.

Almost surely, 2^395666820 is an apocalyptic number.

395666820 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

395666820 is an abundant number, since it is smaller than the sum of its proper divisors (806168724).

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

395666820 is a wasteful number, since it uses less digits than its factorization.

395666820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3029 (or 3024 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The square root of 395666820 is about 19891.3755180480. The cubic root of 395666820 is about 734.1360388537.

The spelling of 395666820 in words is "three hundred ninety-five million, six hundred sixty-six thousand, eight hundred twenty".