21266004100 has 54 divisors (see below), whose sum is σ = 50723842442. Its totient is φ = 7733088000.

The previous prime is 21266004047. The next prime is 21266004103. The reversal of 21266004100 is 140066212.

It can be written as a sum of positive squares in 3 ways, for example, as 412333636 + 20853670464 = 20306^2 + 144408^2 .

It is a super-3 number, since 3×21266004100³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (21266004103) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 866661 + ... + 890860.

Almost surely, 2^21266004100 is an apocalyptic number.

21266004100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21266004100 is an abundant number, since it is smaller than the sum of its proper divisors (29457838342).

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

21266004100 is a wasteful number, since it uses less digits than its factorization.

21266004100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1757557 (or 1757539 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The spelling of 21266004100 in words is "twenty-one billion, two hundred sixty-six million, four thousand, one hundred".