21021121001100 has 72 divisors (see below), whose sum is σ = 66350301933888. Its totient is φ = 5096029332800.

The previous prime is 21021121001087. The next prime is 21021121001113. The reversal of 21021121001100 is 110012112012.

It is an interprime number because it is at equal distance from previous prime (21021121001087) and next prime (21021121001113).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3185015034 + ... + 3185021633.

It is an arithmetic number, because the mean of its divisors is an integer number (921531971304).

Almost surely, 2^{21021121001100} is an apocalyptic number.

21021121001100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021121001100 is an abundant number, since it is smaller than the sum of its proper divisors (45329180932788).

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

21021121001100 is a wasteful number, since it uses less digits than its factorization.

21021121001100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6370036695 (or 6370036688 counting only the distinct ones).

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

Adding to 21021121001100 its reverse (110012112012), we get a palindrome (21131133113112).

The spelling of 21021121001100 in words is "twenty-one trillion, twenty-one billion, one hundred twenty-one million, one thousand, one hundred".