21640060163 has 4 divisors (see below), whose sum is σ = 22580932368. Its totient is φ = 20699187960.

The previous prime is 21640060153. The next prime is 21640060181. The reversal of 21640060163 is 36106004612.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21640060163 - 2³² = 17345092867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21640060103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 470436068 + ... + 470436113.

It is an arithmetic number, because the mean of its divisors is an integer number (5645233092).

Almost surely, 2^21640060163 is an apocalyptic number.

21640060163 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21640060163 is a deficient number, since it is larger than the sum of its proper divisors (940872205).

21640060163 is an equidigital number, since it uses as much as digits as its factorization.

21640060163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 940872204.

The product of its (nonzero) digits is 5184, while the sum is 29.

Adding to 21640060163 its reverse (36106004612), we get a palindrome (57746064775).

The spelling of 21640060163 in words is "twenty-one billion, six hundred forty million, sixty thousand, one hundred sixty-three".