395643989 has 16 divisors (see below), whose sum is σ = 439498752. Its totient is φ = 353844288.

The previous prime is 395643977. The next prime is 395644001. The reversal of 395643989 is 989346593.

It is an interprime number because it is at equal distance from previous prime (395643977) and next prime (395644001).

It is a cyclic number.

It is not a de Polignac number, because 395643989 - 2¹⁶ = 395578453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (395643089) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68207 + ... + 73779.

It is an arithmetic number, because the mean of its divisors is an integer number (27468672).

Almost surely, 2^395643989 is an apocalyptic number.

It is an amenable number.

395643989 is a deficient number, since it is larger than the sum of its proper divisors (43854763).

395643989 is a wasteful number, since it uses less digits than its factorization.

395643989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5756.

The product of its digits is 6298560, while the sum is 56.

The square root of 395643989 is about 19890.8016178333. The cubic root of 395643989 is about 734.1219180653.

The spelling of 395643989 in words is "three hundred ninety-five million, six hundred forty-three thousand, nine hundred eighty-nine".