21201221111000 has 64 divisors (see below), whose sum is σ = 56698122761280. Its totient is φ = 7268990092800.

The previous prime is 21201221110987. The next prime is 21201221111029. The reversal of 21201221111000 is 11112210212.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1514365937 + ... + 1514379936.

It is an arithmetic number, because the mean of its divisors is an integer number (885908168145).

Almost surely, 2^{21201221111000} is an apocalyptic number.

21201221111000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201221111000 is an abundant number, since it is smaller than the sum of its proper divisors (35496901650280).

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

21201221111000 is a wasteful number, since it uses less digits than its factorization.

21201221111000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3028745901 (or 3028745887 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21201221111000 its reverse (11112210212), we get a palindrome (21212333321212).

The spelling of 21201221111000 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-one million, one hundred eleven thousand".