328641561 has 12 divisors (see below), whose sum is σ = 485744688. Its totient is φ = 213998904.

The previous prime is 328641559. The next prime is 328641563. The reversal of 328641561 is 165146823.

It is a happy number.

328641561 is a `hidden beast` number, since 3 + 2 + 8 + 641 + 5 + 6 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (328641559) and next prime (328641563).

It is not a de Polignac number, because 328641561 - 2¹ = 328641559 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (328641563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 424215 + ... + 424988.

It is an arithmetic number, because the mean of its divisors is an integer number (40478724).

Almost surely, 2^328641561 is an apocalyptic number.

It is an amenable number.

328641561 is a deficient number, since it is larger than the sum of its proper divisors (157103127).

328641561 is a wasteful number, since it uses less digits than its factorization.

328641561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 849252 (or 849249 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 328641561 is about 18128.4737636680. The cubic root of 328641561 is about 690.0927978531.

The spelling of 328641561 in words is "three hundred twenty-eight million, six hundred forty-one thousand, five hundred sixty-one".