21310388163 has 24 divisors (see below), whose sum is σ = 32433395280. Its totient is φ = 13446051840.

The previous prime is 21310388153. The next prime is 21310388173. The reversal of 21310388163 is 36188301312.

21310388163 is a `hidden beast` number, since 213 + 1 + 0 + 388 + 1 + 63 = 666.

It is an interprime number because it is at equal distance from previous prime (21310388153) and next prime (21310388173).

It is not a de Polignac number, because 21310388163 - 2⁸ = 21310387907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21310388153) 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, 116323 + ... + 236963.

It is an arithmetic number, because the mean of its divisors is an integer number (1351391470).

Almost surely, 2^21310388163 is an apocalyptic number.

21310388163 is a deficient number, since it is larger than the sum of its proper divisors (11123007117).

21310388163 is a wasteful number, since it uses less digits than its factorization.

21310388163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121699 (or 121696 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

Adding to 21310388163 its reverse (36188301312), we get a palindrome (57498689475).

The spelling of 21310388163 in words is "twenty-one billion, three hundred ten million, three hundred eighty-eight thousand, one hundred sixty-three".