21320740163 has 4 divisors (see below), whose sum is σ = 21342430608. Its totient is φ = 21299049720.

The previous prime is 21320740117. The next prime is 21320740171. The reversal of 21320740163 is 36104702312.

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 21320740163 - 2⁶ = 21320740099 is a prime.

It is a super-2 number, since 2×21320740163² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21320740193) 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, 10843748 + ... + 10845713.

It is an arithmetic number, because the mean of its divisors is an integer number (5335607652).

Almost surely, 2^21320740163 is an apocalyptic number.

21320740163 is a deficient number, since it is larger than the sum of its proper divisors (21690445).

21320740163 is an equidigital number, since it uses as much as digits as its factorization.

21320740163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21690444.

The product of its (nonzero) digits is 6048, while the sum is 29.

The spelling of 21320740163 in words is "twenty-one billion, three hundred twenty million, seven hundred forty thousand, one hundred sixty-three".