21212223100 has 36 divisors (see below), whose sum is σ = 46306192464. Its totient is φ = 8434074880.

The previous prime is 21212223083. The next prime is 21212223113. The reversal of 21212223100 is 132221212.

It is a happy number.

It is a super-2 number, since 2×21212223100² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 618397 + ... + 651796.

It is an arithmetic number, because the mean of its divisors is an integer number (1286283124).

Almost surely, 2^21212223100 is an apocalyptic number.

21212223100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212223100 is an abundant number, since it is smaller than the sum of its proper divisors (25093969364).

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

21212223100 is a wasteful number, since it uses less digits than its factorization.

21212223100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1270374 (or 1270367 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21212223100 its reverse (132221212), we get a palindrome (21344444312).

The spelling of 21212223100 in words is "twenty-one billion, two hundred twelve million, two hundred twenty-three thousand, one hundred".