395131621 has 4 divisors (see below), whose sum is σ = 405810892. Its totient is φ = 384452352.

The previous prime is 395131591. The next prime is 395131691. The reversal of 395131621 is 126131593.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 346480996 + 48650625 = 18614^2 + 6975^2 .

It is a cyclic number.

It is not a de Polignac number, because 395131621 - 2¹¹ = 395129573 is a prime.

It is a super-2 number, since 2×395131621² = 312257995828175282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (395131691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5339580 + ... + 5339653.

It is an arithmetic number, because the mean of its divisors is an integer number (101452723).

Almost surely, 2^395131621 is an apocalyptic number.

It is an amenable number.

395131621 is a deficient number, since it is larger than the sum of its proper divisors (10679271).

395131621 is a wasteful number, since it uses less digits than its factorization.

395131621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10679270.

The product of its digits is 4860, while the sum is 31.

The square root of 395131621 is about 19877.9179241690. The cubic root of 395131621 is about 733.8048796196.

The spelling of 395131621 in words is "three hundred ninety-five million, one hundred thirty-one thousand, six hundred twenty-one".