21275420100 has 288 divisors, whose sum is σ = 71336184192. Its totient is φ = 4838400000.

The previous prime is 21275420099. The next prime is 21275420137. The reversal of 21275420100 is 102457212.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 30349750 + ... + 30350450.

It is an arithmetic number, because the mean of its divisors is an integer number (247695084).

Almost surely, 2^21275420100 is an apocalyptic number.

21275420100 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 21275420100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35668092096).

21275420100 is an abundant number, since it is smaller than the sum of its proper divisors (50060764092).

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

21275420100 is a wasteful number, since it uses less digits than its factorization.

21275420100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1287 (or 1280 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 24.

Adding to 21275420100 its reverse (102457212), we get a palindrome (21377877312).

The spelling of 21275420100 in words is "twenty-one billion, two hundred seventy-five million, four hundred twenty thousand, one hundred".