21163451000 has 64 divisors (see below), whose sum is σ = 49771800000. Its totient is φ = 8422761600.

The previous prime is 21163450999. The next prime is 21163451027. The reversal of 21163451000 is 15436112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 145826 + ... + 252174.

It is an arithmetic number, because the mean of its divisors is an integer number (777684375).

Almost surely, 2^21163451000 is an apocalyptic number.

21163451000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21163451000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24885900000).

21163451000 is an abundant number, since it is smaller than the sum of its proper divisors (28608349000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21163451000 is a wasteful number, since it uses less digits than its factorization.

21163451000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106569 (or 106555 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

Adding to 21163451000 its reverse (15436112), we get a palindrome (21178887112).

The spelling of 21163451000 in words is "twenty-one billion, one hundred sixty-three million, four hundred fifty-one thousand".