21111210100 has 36 divisors (see below), whose sum is σ = 47803127904. Its totient is φ = 8077331680.

The previous prime is 21111210089. The next prime is 21111210119. The reversal of 21111210100 is 101211112.

It is a Harshad number since it is a multiple of its sum of digits (10).

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, 4587094 + ... + 4591693.

It is an arithmetic number, because the mean of its divisors is an integer number (1327864664).

Almost surely, 2^21111210100 is an apocalyptic number.

21111210100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111210100 is an abundant number, since it is smaller than the sum of its proper divisors (26691917804).

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

21111210100 is a wasteful number, since it uses less digits than its factorization.

21111210100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9178824 (or 9178817 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21111210100 its reverse (101211112), we get a palindrome (21212421212).

The spelling of 21111210100 in words is "twenty-one billion, one hundred eleven million, two hundred ten thousand, one hundred".