395138661 has 4 divisors (see below), whose sum is σ = 526851552. Its totient is φ = 263425772.

The previous prime is 395138647. The next prime is 395138671. The reversal of 395138661 is 166831593.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166831593 = 3 ⋅55610531.

It is a cyclic number.

It is not a de Polignac number, because 395138661 - 2²² = 390944357 is a prime.

It is a super-2 number, since 2×395138661² = 312269122833745842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (395138641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65856441 + ... + 65856446.

It is an arithmetic number, because the mean of its divisors is an integer number (131712888).

Almost surely, 2^395138661 is an apocalyptic number.

It is an amenable number.

395138661 is a deficient number, since it is larger than the sum of its proper divisors (131712891).

395138661 is a wasteful number, since it uses less digits than its factorization.

395138661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131712890.

The product of its digits is 116640, while the sum is 42.

The square root of 395138661 is about 19878.0950043006. The cubic root of 395138661 is about 733.8092376237.

The spelling of 395138661 in words is "three hundred ninety-five million, one hundred thirty-eight thousand, six hundred sixty-one".