163640641 has 2 divisors, whose sum is σ = 163640642. Its totient is φ = 163640640.

The previous prime is 163640639. The next prime is 163640693. The reversal of 163640641 is 146046361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 151807041 + 11833600 = 12321^2 + 3440^2 .

It is a cyclic number.

It is not a de Polignac number, because 163640641 - 2¹ = 163640639 is a prime.

Together with 163640639, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (163640341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81820320 + 81820321.

It is an arithmetic number, because the mean of its divisors is an integer number (81820321).

Almost surely, 2^163640641 is an apocalyptic number.

It is an amenable number.

163640641 is a deficient number, since it is larger than the sum of its proper divisors (1).

163640641 is an equidigital number, since it uses as much as digits as its factorization.

163640641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 163640641 is about 12792.2101686925. The cubic root of 163640641 is about 546.9702733428.

The spelling of 163640641 in words is "one hundred sixty-three million, six hundred forty thousand, six hundred forty-one".