21211112100 has 72 divisors (see below), whose sum is σ = 63029521408. Its totient is φ = 5503420800.

The previous prime is 21211112017. The next prime is 21211112147. The reversal of 21211112100 is 121111212.

It is a super-6 number, since 6×21211112100⁶ (a number of 63 digits) contains 666666 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 944356 + ... + 966555.

Almost surely, 2^21211112100 is an apocalyptic number.

21211112100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211112100 is an abundant number, since it is smaller than the sum of its proper divisors (41818409308).

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

21211112100 is a wasteful number, since it uses less digits than its factorization.

21211112100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1910965 (or 1910958 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21211112100 its reverse (121111212), we get a palindrome (21332223312).

It can be divided in two parts, 21211112 and 100, that added together give a palindrome (21211212).

The spelling of 21211112100 in words is "twenty-one billion, two hundred eleven million, one hundred twelve thousand, one hundred".