163778961 has 16 divisors (see below), whose sum is σ = 224132480. Its totient is φ = 106341120.

The previous prime is 163778941. The next prime is 163778963. The reversal of 163778961 is 169877361.

It is a happy number.

It is not a de Polignac number, because 163778961 - 2¹⁰ = 163777937 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 163778961.

It is not an unprimeable number, because it can be changed into a prime (163778963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14505 + ... + 23193.

It is an arithmetic number, because the mean of its divisors is an integer number (14008280).

Almost surely, 2^163778961 is an apocalyptic number.

It is an amenable number.

163778961 is a deficient number, since it is larger than the sum of its proper divisors (60353519).

163778961 is a wasteful number, since it uses less digits than its factorization.

163778961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8856.

The product of its digits is 381024, while the sum is 48.

The square root of 163778961 is about 12797.6154419486. The cubic root of 163778961 is about 547.1243418778.

The spelling of 163778961 in words is "one hundred sixty-three million, seven hundred seventy-eight thousand, nine hundred sixty-one".