21563262100 has 72 divisors (see below), whose sum is σ = 49093968896. Its totient is φ = 8210160000.

The previous prime is 21563261969. The next prime is 21563262109. The reversal of 21563262100 is 126236512.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21563262109) 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, 132085 + ... + 246115.

Almost surely, 2^21563262100 is an apocalyptic number.

21563262100 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 21563262100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24546984448).

21563262100 is an abundant number, since it is smaller than the sum of its proper divisors (27530706796).

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

21563262100 is a wasteful number, since it uses less digits than its factorization.

21563262100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114137 (or 114130 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

Adding to 21563262100 its reverse (126236512), we get a palindrome (21689498612).

The spelling of 21563262100 in words is "twenty-one billion, five hundred sixty-three million, two hundred sixty-two thousand, one hundred".