21003342100 has 72 divisors (see below), whose sum is σ = 49589504888. Its totient is φ = 7675084800.

The previous prime is 21003342071. The next prime is 21003342109. The reversal of 21003342100 is 124330012.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 5974053264 + 15029288836 = 77292^2 + 122594^2 .

It is a super-2 number, since 2×21003342100² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003342109) 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, 42820 + ... + 209380.

Almost surely, 2^21003342100 is an apocalyptic number.

21003342100 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 21003342100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24794752444).

21003342100 is an abundant number, since it is smaller than the sum of its proper divisors (28586162788).

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

21003342100 is a wasteful number, since it uses less digits than its factorization.

21003342100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166685 (or 166678 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 21003342100 its reverse (124330012), we get a palindrome (21127672112).

The spelling of 21003342100 in words is "twenty-one billion, three million, three hundred forty-two thousand, one hundred".