21203020100 has 18 divisors (see below), whose sum is σ = 46010553834. Its totient is φ = 8481208000.

The previous prime is 21203020093. The next prime is 21203020127. The reversal of 21203020100 is 102030212.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 1246937344 + 19956082756 = 35312^2 + 141266^2 .

It is a super-2 number, since 2×21203020100² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 106015001 + ... + 106015200.

Almost surely, 2^21203020100 is an apocalyptic number.

21203020100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21203020100 is an abundant number, since it is smaller than the sum of its proper divisors (24807533734).

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

21203020100 is a wasteful number, since it uses less digits than its factorization.

21203020100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212030215 (or 212030208 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

Adding to 21203020100 its reverse (102030212), we get a palindrome (21305050312).

The spelling of 21203020100 in words is "twenty-one billion, two hundred three million, twenty thousand, one hundred".