21550320100 has 36 divisors (see below), whose sum is σ = 46797004800. Its totient is φ = 8614080160.

The previous prime is 21550320067. The next prime is 21550320109. The reversal of 21550320100 is 102305512.

It is not an unprimeable number, because it can be changed into a prime (21550320109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69021 + ... + 218779.

It is an arithmetic number, because the mean of its divisors is an integer number (1299916800).

Almost surely, 2^21550320100 is an apocalyptic number.

21550320100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21550320100 is an abundant number, since it is smaller than the sum of its proper divisors (25246684700).

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

21550320100 is a wasteful number, since it uses less digits than its factorization.

21550320100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151212 (or 151205 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 19.

Adding to 21550320100 its reverse (102305512), we get a palindrome (21652625612).

The spelling of 21550320100 in words is "twenty-one billion, five hundred fifty million, three hundred twenty thousand, one hundred".