21163161600 has 792 divisors, whose sum is σ = 89951195880. Its totient is φ = 4837294080.

The previous prime is 21163161583. The next prime is 21163161601. The reversal of 21163161600 is 616136112.

21163161600 is a `hidden beast` number, since 2 + 1 + 16 + 31 + 616 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21163161601) by changing a digit.

It is a polite number, since it can be written in 65 ways as a sum of consecutive naturals, for example, 3023308797 + ... + 3023308803.

Almost surely, 2^21163161600 is an apocalyptic number.

21163161600 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 21163161600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44975597940).

21163161600 is an abundant number, since it is smaller than the sum of its proper divisors (68788034280).

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

21163161600 is an frugal number, since it uses more digits than its factorization.

21163161600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

Adding to 21163161600 its reverse (616136112), we get a palindrome (21779297712).

The spelling of 21163161600 in words is "twenty-one billion, one hundred sixty-three million, one hundred sixty-one thousand, six hundred".