163878561 has 24 divisors (see below), whose sum is σ = 295124544. Its totient is φ = 85131360.

The previous prime is 163878551. The next prime is 163878569. The reversal of 163878561 is 165878361.

163878561 is a `hidden beast` number, since 1 + 6 + 3 + 87 + 8 + 561 = 666.

It is not a de Polignac number, because 163878561 - 2¹¹ = 163876513 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (163878569) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 117546 + ... + 118931.

It is an arithmetic number, because the mean of its divisors is an integer number (12296856).

Almost surely, 2^163878561 is an apocalyptic number.

163878561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

163878561 is a deficient number, since it is larger than the sum of its proper divisors (131245983).

163878561 is a wasteful number, since it uses less digits than its factorization.

163878561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236501 (or 236498 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 163878561 is about 12801.5062004438. The cubic root of 163878561 is about 547.2352282035.

The spelling of 163878561 in words is "one hundred sixty-three million, eight hundred seventy-eight thousand, five hundred sixty-one".